a123.g.akamai.neta123.g.akamai.net/7/123/11558/abc123/forestservic...Human Health Risk Assessment For the Moonlight Restoration Project . Natalie Morgan . May 2. nd, 2017 . In accordance

Human Health Risk Assessment For the Moonlight Restoration Project

Natalie Morgan

May 2nd, 2017

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Contents Human Health Risk Assessment ................................................................................................................... 1 For the Moonlight Restoration Project.......................................................................................................... 1

Direction for Pesticide-Use Management and Coordination .................................................................... 1 Compliance with Direction: ...................................................................................................................... 1 Section 1 - Introduction ............................................................................................................................ 2 Section 2 - Hazard Analysis ..................................................................................................................... 4

2.1 Impurities and Metabolites .............................................................................................................. 5 2.2 Additives ......................................................................................................................................... 6

Section 3 - Exposure Analysis .................................................................................................................. 8 3.1 Worker Exposure ............................................................................................................................ 8 3.2 Public Exposure .............................................................................................................................. 9

Section 4 - Dose – Response Assessment............................................................................................... 11 Section 5 - Risk Characterization ........................................................................................................... 11

5.1 Glyphosate .................................................................................................................................... 11 5.2 Triclopyr Triethylamine Salt ......................................................................................................... 15 5.3 3,5,6-trichloro-2-pyridinol ............................................................................................................ 17 5.4 Borate Salt (Disodium Octaborate Tetrahydrate) ......................................................................... 18 5.5 Sensitive Individuals ..................................................................................................................... 20 5.6 Synergistic Effects ........................................................................................................................ 21 5.7 Cumulative Effects ........................................................................................................................ 22

References .............................................................................................................................................. 28 Appendix A – Exposure Scenarios ............................................................................................................. 31

Worker Exposure Scenarios – Glyphosate ............................................................................................. 31 Public Exposure Scenarios - Glyphosate ................................................................................................ 31 Worker Exposure Scenarios – Triclopyr Triethylamine Salt.................................................................. 33 Public Exposure Scenarios - Triclopyr Triethylamine Salt .................................................................... 33 Public Exposure Scenarios - 3,5,6-Trichloro-2-Pyridinol ...................................................................... 34 Worker Exposure Scenarios – Borate Salt (Disodium Octaborate Tetrahydrate) .................................. 35 Public Exposure Scenarios - Borate Salt (Disodium Octaborate Tetrahydrate) ..................................... 35

List of Tables Table 1. Description of chemical formulation, application rate and type, and additives proposed for use in

the Moonlight Restoration Project ........................................................................................................ 3 Table 2. Peak water contamination rates for selected pesticides ................................................................ 10 Table 3 Reference doses of proposed pesticides ......................................................................................... 11 Table 4 Summary of risk characterization for workers – Glyphosate 1.2 lbs acid equivalent /acre ........... 12 Table 5 Summary of risk characterization for workers – Glyphosate 6 lbs acid equivalent /acre .............. 12 Table 6 Summary of risk characterizations for the general public – Glyphosate 1.2 lbs acid

equivalent/acre .................................................................................................................................... 13 Table 7 Summary of risk characterizations for the general public – Glyphosate 6 lbs acid equivalent/acre

............................................................................................................................................................ 14 Table 8. Summary of risk characterization for workers – Triclopyr triethylamine salt 1 lb acid equivalent

/acre ..................................................................................................................................................... 15 Table 9. Summary of risk characterizations for the general public – Triclopyr triethylamine salt 1 lb acid

equivalent/acre .................................................................................................................................... 16 Table 10. Summary of risk characterizations for the general public – 3,5,6-trichloro-2-pyridinol 1 lb acid

equivalent /acre ................................................................................................................................... 18


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Table 11. Summary of risk characterization for workers – borate salt (disodium octaborate tetrahydrate) 0.5 lbs/acre .......................................................................................................................................... 19

Table 12. Summary of risk characterizations for the general public – borate salt (disodium octaborate tetrahydrate) 0.5 lbs/acre ..................................................................................................................... 19

Table 13. Summary of worker exposure scenarios – Glyphosate 1.2 lbs acid equivalent/acre .................. 31 Table 14. Summary of worker exposure scenarios – Glyphosate 7 lbs acid equivalent /acre .................... 31 Table 15. Summary of public exposure scenarios – Glyphosate 6 lbs acid equivalent/acre ....................... 31 Table 16. Summary of public exposure scenarios – Glyphosate 6 lbs acid equivalent /acre ...................... 32 Table 17. Summary of worker exposure scenarios – Triclopyr triethylamine salt 1 lb acid equivalent/acre

............................................................................................................................................................ 33 Table 18. Summary of public exposure scenarios – Triclopyr triethylamine salt 1 lb acid equivalent/acre

............................................................................................................................................................ 33 Table 19. Summary of public exposure scenarios – triethylamine salt 1 lb acid equivalent/acre ............... 34 Table 20. Summary of worker exposure scenarios – borate salt disodium octaborate tetrahydrate 0.5

lbs/acre ................................................................................................................................................ 35 Table 21. Summary of public exposure scenarios – borate salt disodium octaborate tetrahydrate 0.5

lbs/acre ................................................................................................................................................ 35


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Direction for Pesticide-Use Management and Coordination Forest Service Manual (FSM) 2150 and Forest Service Handbook (FSH) 2109.14 provide direction to provide for pesticide use safety for public and employees from unsafe work conditions when pesticides are involved. Development of a pesticide risk assessment is a part of this planning process. A pesticide risk assessment does not, in itself, ensure safety in pesticide use. The analysis must be tied to an action plan which provides mitigation measures to avoid potential risks identified by the risk assessment.

FSH 2109.14, 20 provides direction on the components of a risk analysis, documentation of risk analysis, risk management, risk communication and risk takings.

• Upon completion of a risk analysis, a number of techniques can be used to determine the best course of action for preventing identified problems. These range from taking appropriate mitigation measures to reduce risk, to not pursing the proposed action, thus avoiding potential risks.

• Use risk analyses to decide whether, and to what extent, controls on exposure are necessary to protect public health and the environment.

• Managers and decision makers must also recognize the uncertainties associated with risk analyses and incorporate those considerations into their decision making.

Compliance with Direction: • Use risk analyses to decide whether, and to what extent, controls on exposure are necessary to

protect public health and the environment.

♦ Syracuse Environmental Research Associates Inc. (SERA). 1997a. Use and assessment of Marker Dyes used with Herbicides. December 21, 1997. SERA TR 96-21-07-03b. Fayetteville, New York. 47 pages.

♦ SERA. 1997b. Effects of Surfactants on the Toxicity of Glyphosate, with Specific Reference to Rodeo. SERA TR97-206-1b. 32 pages.

♦ SERA. 2002. Neurotoxicity, Immunotoxicity, and Endocrine Disruption with Specific Commentary on Glyphosate, Triclopyr, and Hexazinone: Final Report. February 14, 2002. SERA TR-01-43-08-04a. 55 pages.

♦ SERA. 2010. Appendices to Glyphosate Human Health and Ecological Risk Assessment – Final Report. November 29, 2010. SERA TR-052-22-03a-APP. 123 pages.

♦ SERA. 2011. Glyphosate Human Health and Ecological Risk Assessment – Final Report. March 25, 2011. SERA TR-052-22-03b. Manlius, New York. 336 pages.

♦ SERA. 2016. Sporax and Cellu-treat (Selected Borate Salts) Human Health and Ecological Risk Assessment – Final Report. October 17, 2016. SERA TR-056-15-03c. Manilus, New York. 236 pages.

♦ SERA. 2016. Triclopyr Human Health and Ecological Risk Assessment – Corrected Final Report. July 9, 2016. SERA TR0-052-25-03c. Manilus, New York. 251 pages.

♦ USDA Forest Service. 2000. Consideration of Cancer Risk with Colorfast Purple Dye Unpublished report written by David Bakke, Pacific Southwest Regional Pesticide-Use Specialist. 1 page.


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♦ USDA Forest Service. 2002 and 2007 update. Analysis of issues surrounding the use of spray adjuvants with herbicides. Unpublished report written by David Bakke, Pacific Southwest Regional Pesticide-Use Specialist. 61 pages.

• Forest Service Software Program WorksheetMaker Version 6.01.16 was used to generate computational spreadsheets for each pesticide formulation proposed for application (glyphosate, triclopyr TEA and DOT). These documents are available in the planning record and have been used to identify potential areas of higher risk, and also to document the risk analysis process. The pesticide application rate will vary across the project area and will depend on the on-site conditions. For this analysis worksheets were compiled for application rates for both the low and high range applications rates for glyphosate, and individual rates for triclopyr and cellu-treat®.

• Design criteria have been developed to mitigate risks identified from pesticide application.

• Public participation through the National Environmental Policy Act (NEPA) process has provided a purposeful exchanged of information about health or environmental risks between interested parties.

Section 1 - Introduction The purpose of this analysis is to assess the risks of pesticides proposed for use in the Moonlight restoration project. The two herbicide active ingredients are glyphosate (N-(phosophonomethyl) glycine), and triclopyr ([(3,5,6-trichloro-2-pyridinly)oxy]acetic acid. The formulation of triclopyr acid proposed for application is triethylamine salt. The fungicide proposed for use in this project is borate salt (disodium octaborate tetrahydrate). The below tables gives a description of proposed pesticide uses and formulations.


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Table 1. Description of chemical formulation, application rate and type, and additives proposed for use in the Moonlight Restoration Project

Pesticide Trade Names Target Species Timing Max

oz/acre

Proposed Application

Rate

Proposed Application

Methods Mix % Worksheet

Gallons/acre Adjuvant

Glyphosate Rodeo® or equivalent

Ceanothus species Manzanita Chinquapin

Bitter Cherry

Spring when target

plants are actively growing

38-192 1.2 to 6 lbs a.e./acre

Backpack directed

foliar spray 2-6% 20 (15-25) Non-ionic

surfactant

Triclopyr triethylamine

salt

Garlon 3A™ or

equivalent

Ceanothus species Manzanita Chinquapin

Bitter Cherry

Spring when target

plants are actively growing

38 - 64 1.0 lb a.e/acre Backpack directed

foliar spray 2% 20 (15-25) Non-ionic

surfactant

Borate salt (disodium octaborate

tetrahydrate)

Cellu-treat® Heterobasidion spp. Recently harvested

trees 8-16 0.5 lbs /acre Stump

application 5% 1 None

Adjuvant Trade Names

Spreader-Penetrator

Hasten, Competitor

(aquatic formulation)

1%

Spreader-Penetrator Syl-Tac 1%

Marker Dye Colorfast Purple 0.04%

Marker Dye Hi-Light Blue 0.25%


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This risk assessment examines the potential health effects on all groups of people who might be exposed to any of the pesticides that are proposed in this project. Those potentially at risk fall into two groups: workers, and members of the general public. Workers include applicators, supervisors, and other personnel directly involved in the application of pesticides. The public includes forest users or nearby residents who could be exposed through the drift of pesticide droplets, through contact with sprayed vegetation, or by eating or placing in the mouth food items or other plant material including berries or shoots growing in or near the forest, game or fish, or direct water consumption containing such residues.

Much of the information used in this risk assessment was gathered from pesticide specific risk assessments completed by Syracuse Environmental Research Associates, Inc., under contract to the Forest Service. The analysis of the potential human health effects of the use of pesticides was accomplished using the risk assessment methodology generally accepted by the scientific community (National Research Council 1983; U.S. Environmental Protection Agency 1986). In essence, this pesticide risk assessment consists of comparing doses that people may get from applying the pesticide (worker doses) or from being near and application site (public doses) with the U.S. Environmental Protection Agency (EPA) established reference doses, a level of exposure that results in no adverse effect over a lifetime or chronic exposures.

The site specific risk assessment also examines the potential for these treatments to cause synergistic effects, cumulative effects, and effects on sensitive individuals, including women and children. For each type of dose assumed for workers and the public, a hazard quotient was computed by dividing the dose by the reference dose. In general, if the hazard quotient is less than or equal to 1, the risk of effects is considered negligible. Because hazard quotient values are based on reference doses, which are thresholds for cumulative exposure, they consider acute exposures. This aspect is discussed below in the evaluation of possible effects. The computation of the hazard quotient is independent of the amount of acres proposed for treatment in this project.

One of the primary uses of a risk assessment is risk management. Decision makers can use the risk assessment to identify those pesticides, application methods, or exposure rates that pose the greatest risks to workers and the public, and apply appropriate project design criteria and mitigation measures to minimize the risk of exposure. To facilitate this decision-making, acceptable risk levels must be established. EPA has established a significant cancer risk level of 1 chance in a million: the State of California, through Proposition 65, has established a standard of 1 chance in 1 hundred thousand. The reference dose is also an EPA-established measure of acceptable risk for non-carcinogen exposures. This assessment uses the standard of 1 chance in 1 million for cancer risk and the reference dose for non-carcinogen exposures.

This risk assessment is divided into five major sections: 1) introduction; 2) identification of hazards associated with each pesticide and it commercial formulations; 3) assessment of potential exposure to the product; 4) assessment of the dose-response relationship; 5) a characterization of the risk associated with plausible levels of exposure including a discussion about sensitive individuals, synergistic effects, and cumulative effects.

Section 2 - Hazard Analysis A considerable body of information has been compiled in a group of risk assessments completed by SERA (authored by Dr. Patrick Durkin, PhD) under contract to the Forest Service. Toxicity information for the surfactants is summarized in USDA Forest Service 2002 (updated 2007). Current peer-reviewed articles from the public scientific literature, as well as recent EPA documents, were also used to update information contained in these reference documents.


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The toxicological database for each pesticide was reviewed for acute, sub-chronic, and chronic effects on test animals. Because of the obvious limitations on the testing of chemicals on humans, judgments about the potential hazards of pesticides to humans is necessarily based in large part on the results of toxicity tests on laboratory animals. Where such information is available, information on actual human poisoning incidents and effects on human populations supplement these test results. For a background discussion of the various toxicological tests and endpoints, refer to USDA Forest Service (1989).

2.1 Impurities and Metabolites Virtually no chemical synthesis yields a totally pure product. Technical grade pesticides, as with other technical grade products, contain some impurities. The EPA defines the term impurity as “…any substance…in a pesticide product other than an active ingredient or an inert ingredient, including untreated starting materials, side reaction products, contaminants, and degradation products (40 CFR 158.153[d]). To some extent, concern for impurities in technical grade pesticides is reduced by the fact that existing toxicity studies of these pesticides were conducted using technical grade products. Thus, if toxic impurities are present in a technical grade product, their effects are reflected in the toxicity measurements. An exception to this general rule involves carcinogens, most of which are presumed to pose risks in any concentrations.

For this risk assessment pesticides under consideration with toxic impurities and metabolites are:

• Ethylene oxide potentially in surfactant

• 1,4 dioxane potentially in surfactant

• aminomethyl phosphonate (AMPA) in glyphosate

• N-nitrosoglyphosate (NNG)

• 3,5,6-trichloro-2-pyridinol (TCP) in triclopyr

Risk of cancer from exposure to ethylene oxide is considered negligible for occupationally exposed individuals, based on a standard of acceptable risk of 1 in 1 million (USDA Forest Service 2003). Risks from exposure to ethylene oxide are considered acceptable (USDA Forest Service 2003), given the conservative assumptions about exposure. Risks of cancer from the exposure to 1,4-dioxane are considered negligible for occupationally exposed individuals, based on a standard of acceptable risk of 1 in 1 million (Borrecco and Neisess 1991). Accordingly, risks from ethylene oxide and 1,4-dioxane exposures are considered acceptable and will not be further analyzed or discussed further.

Glyphosate is not extensively metabolized. The primary metabolite of glyphosate in mammals and other organisms is aminomethyl phosphonate. Aminomethyl phosphonate is formed in environmental media such as soil and water as a breakdown product of glyphosate. Differences in metabolic pathways can be an important consideration regarding differences in species sensitivity to some chemical agents. There is no indication, however, that this is an important consideration for glyphosate. Because glyphosate is not extensively metabolized, differences in metabolic pathways are not likely to be an important consideration in extrapolations from animal toxicity data to potential risks in humans (Syracuse Environmental Research Associates Inc. 2011). Thus, in terms of assessing direct exposures to technical grade glyphosate, the inherent exposures to aminomethyl phosphonate as a metabolite are encompassed by the existing toxicity data on glyphosate. Based on the available information on glyphosate the U.S. Environmental Protection Agency, Office of Pesticide Programs (1993) has classified the chemical as Group E (evidence of non-carcinogenicity for humans); therefore no quantitative risk assessment for cancer is conducted as part of the current Forest Service risk assessment (Syracuse Environmental


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Research Associates Inc. 2011). The carcinogenicity of glyphosate is further discussed in the cumulative effects section of this risk assessment.

N-nitrosoglyphosate contains the nitrosoamine group which are nitroso compounds in which the nitroso group is attached to a nitrogen atom, N-N=O. Certain groups of nitrosoamines have served as model compounds in some of the classical studies on chemical carcinogenicity. While there is a general concern for the carcinogenic potential of nitroso compounds, the contribution of specific nitroso compounds to carcinogenic risk is difficult to quantify (Mirvish 1995). The EPA has concluded based on research that the N-nitrosoglyphosate content of technical grade glyphosate was not toxicologically significant (EPA re-registration document (RED). As with aminomethyl phosphonate, a detailed dose-response and exposure assessment for N-nitrosoglyphosate does not appear to be warranted and will not be further analyzed or discussed further in this assessment.

As with impurities, the potential effects of metabolites is encompassed by the available in vivo toxicity studies, under the assumption that toxicological consequences of metabolism in the species tested would be similar to those of humans. Uncertainties in this assumption are countered by using an uncertainty factor in deriving the reference doses and relying upon conservative studies in determining the appropriate reference doses.

The major metabolite of triclopyr in both mammals and the environment is 3,5,6-trichloro-2-pyridinol, commonly abbreviated as TCP. Although 3,5,6-trichloro-2-pyridinol does not have the phytotoxic potency of triclopyr, this compound is toxic to mammals as well as other species. Based on current studies 3,5,6-trichloro-2-pyridinol has been found to be more toxic than triclopyr triethylamine salt (TEA) by a factor of about 40, based on acute toxicity, and by a factor of 180, based on chronic toxicity (Syracuse Environmental Research Associates Inc. 2016a). Consequently, the acute and chronic reference doses for 3,5,6-trichloro-2-pyridinol derived by U.S. Environmental Protection Agency, Office of Pesticide Programs are below the corresponding reference doses derived by the U.S. Environmental Protection Agency, Office of Pesticide Programs. The potential health effects of 3,5,6-trichloro-2-pyridinol exposure are therefore analyzed separately in this risk assessment.

2.2 Additives Additives involve surfactants, drift reduction agents, and dyes or colorants. Many of the formulated pesticides require the use of added surfactants; such information is on the pesticide label. Surfactants increase the ability of the pesticide to be absorbed into plant tissue. Dyes and colorants are used to indicate that a plant or area has been treated to avoid the waste re-treatment, allow people to avoid treated areas in the short term, and assure good coverage of target vegetation.

Additives, or adjuvants, to the formulations when pesticides are applied include a surfactant Syl-Tac® or Hasten® (also available as Competitor®)

Syl-Tac®, which has a “Caution” signal word. It may cause slight skin and eye irritation. Syl-Tac®is of low acute oral and dermal toxicity. Syl-Tac® is a blend of two other products; Hasten®, a vegetable oil based surfactant, and Sylgard 309, and organosilicone surfactant.

Hasten® (and Competitor®) has a “Caution” signal word. Hasten® may be mildly irritating to the skin and to the eyes. The product is of low acute oral and dermal toxicity. The main ingredient in Hasten® is identified in Wilbur-Ellis product information as ethylated corn, canola, and soybean oil (a regulated food additive under 21 CFR 172.515. l). This is combined with sorbitan alkylethoxylate ester as a nonionic surfactant. The polyoxyethylene dialkylester is not sufficiently identified to say anything definite about its composition or toxicity. Hasten® contains ethoxylated ingredients. Ethoxylates are formed by reactions of


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ethylene oxide. In the manufacturing process, some unreacted ethylene oxide as well as the contaminant 1,4-dioxane can become part of the final formulation. Both of these chemicals are considered likely human carcinogens, and are discussed above under impurities and metabolites.

Sylgard® 309 has a Warning signal word. It is considered slightly irritating to the skin and is considered severely irritating to the eyes. It is not a skin sensitizer. The main ingredients of Sylgard® 309 are a mixture of three siloxanes and silicones (3-(3-hydroxypropyl) heptamethyltrisiloxane, ethoxylated acetate (CAS 125997-17-3) EPA List 4B, polyethylene glycol monallyl acetate (CAS 27252-87-5) EPA List 3, and polyethylene glycol diacetate (CAS 27252-83-1) EPA List 3. The material safety data sheet describes a 28-day oral dosing study in rats, in which rats were fed doses of 0, 33, 300, or 1,000 mg/kg/day. No significant findings of biological relevance were seen in females, while males showed some effects at highest dose (body weight gain, and changes in food consumption). This would indicate a sub-chronic no effect level (NOEL) of 300 mg/kg/day.

An analysis of the ingredients in Syl-Tac® (USDA Forest Service 2007) did not identify any of specific toxic concern with the exception of the ingredients discussed in this risk assessment. None were on the U.S. EPA Lists 1 or 2. The primary summary statement that can be made for the use of Syl-Tac® is that the more common risk factors are through skin or eye exposure. Syl-Tac® carries a “Caution” label. This indicates the need for good industrial hygiene practices while utilizing this product, especially when handling the concentrate, such as during mixing. The use of chemical resistant gloves and goggles, especially while mixing, would reduce the potential for exposure. Nothing in the ingredients in Syl-Tac® indicates a unique hazard or specific toxic concern.

The colorant (Colorfast® Purple) contains a dye, Basic Violet 3 or Gentian Violet, which is considered a potential carcinogen. A risk assessment for the carcinogenic properties of this dye was conducted (SERA 1997a), which concluded that the cancer risk to workers and the public is within the range of acceptable risk. Use of the dye would be expected to reduce public exposure to the pesticide and adjuvant used because the public would be alerted to the presence of treated vegetation. As Syracuse Environmental Research Associates Inc. (1997a) adequately analyze the health risks of using this dye, it is not discussed further in this document.

The colorant (Hi-Light® Blue dye) is not required to be registered as a pesticide; therefore it has no signal word associated with it. It is mildly irritating to the skin and eyes. It would likely be considered a Category III or IV material and have a Caution signal word if it carried one. Hi-Light® Blue is a water-soluble dye that contains no listed hazardous substances. It is considered to be virtually non-toxic to humans. Its effect on non-target terrestrial and aquatic species is unknown; however its use has not resulted in any known problems. The dye used in Hi-Light® Blue is commonly used in toilet bowl cleaners and as a colorant for lakes and ponds (Syracuse Environmental Research Associates Inc. 1997a).

Some formulations of triclopyr triethylamine salt contain the triethylamine salt of triclopyr as well as emulsifiers, surfactants, and ethanol. Triethylamine salt dissociates extremely rapidly to triclopyr acid and trimethylamine; however, relatively little information is available on the toxicity of trimethylamine in triethylamine salt (Syracuse Environmental Research Associates Inc. 2016a). The oral LD50

1 of triclopyr triethylamine salt (as Garlon 3A™) is 828 mg acid equivalent /kg body weight in male rats and 594 mg acid equivalent/kg body weight in female rats (Mizell and Lomax 1988, as referenced in Syracuse Environmental Research Associates Inc. 2016a). These LD50 values are very similar to oral LD50 of triclopyr acid – i.e., 729 mg/kg in male rats and 630 mg/kg in female rats. Consequently, the toxicity of

1 LD50 is the amount of chemical required to provide a “lethal dose” to 50 percent of the test population.


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this triclopyr formulation is consistent with the assumption that the agent of concern in the triclopyr triethylamine salt formulation is triclopyr rather than the triethylamine salt moiety (SERA 2016a).

The triclopyr formulation proposed for use in the Moonlight project Garlon 3A™ contains ethanol an inert ingredient which is classified as toxic. Ethanol is extremely well characterized in humans, and the hazards of exposure include intoxication from acute exposure as well as liver cirrhosis and fetal alcohol syndrome (World Health Organization 1988, as referenced in Syracuse Environmental Research Associates Inc. 2016a). For chronic exposure, the alcohol contained in Garlon 3A™ will not be of toxicological significance because of the rapid breakdown of alcohol in the environment and the relatively high levels of alcohol associated with chronic alcohol poisoning (Syracuse Environmental Research Associates Inc. 2016a).

Section 3 - Exposure Analysis

3.1 Worker Exposure Pesticide applicators are the individuals most likely to be exposed to a pesticide during the application process. For this risk assessment two types of worker exposure scenarios are considered: general and accidental/incidental. The term general exposure scenario is used to designate those exposures that involve estimates of the absorbed dose based on the handling of a specific amount of a chemical during particular types of applications. The accidental/incidental exposure scenarios involve specific types of events that could occur during any type of application.

Exposure rates are shown as milligrams of chemical per kilogram of body weight per pound of active ingredient applied. Based on Syracuse Environmental Research Associates Inc. review, the estimated typical exposure rate for directed foliar applications involving the use of backpacks or similar devices is 0.003 mg/kg/lb active ingredient, with a lower and upper range of .0003 and 0.01 mg/kg/lb active ingredient. The exposure of workers is based on the number of hours worked per day, acres treated per hour, and the application rates for the various pesticides. Rather than focus on a single value, each of these factors involves a range of values, which when combined created three levels of exposure (central (proposed), lower, and upper)). Central levels are based on proposed application rates and recent experience on adjacent national forests. The upper level is a worst-case level, based on the highest application rates, the least dilution and the largest acreage treated per day. The lower level is used as a lower limit, based on lower applications rates, most dilution, and lowest acres per day treated. For most exposure scenarios, exposure and consequent risk will scale linearly with the application rate, and the consequences of using lower or higher application rates are considered in the risk characterization.

In general, occupational exposures may involve multiple routes of exposure (oral, dermal, and inhalation); nonetheless, dermal exposure is generally the predominant route for pesticide applicators. Typical multi-route exposures are encompassed by methods used for general exposures. Accidental exposures, on the other hand, are most likely to involve splashing pesticides in to the eyes or onto the skin.

There are various methods for estimating absorbed doses associated with accidental dermal exposure. Two general types of exposure are modeled: 1) those involving direct contact with a solution of the pesticide; and 2) those associated with accidental spills of the pesticide onto the surface of the skin. Any number of exposure scenarios could be developed for direct contact or accidental spills by varying the amount or concentration of the chemical contacting the skin and the surface area of the skin that is contaminated. For this risk assessment, two exposure scenarios are developed for each of the two types of dermal exposure, and the estimated dose for each scenario is expressed in units of milligrams of chemical per kilogram body weight (mg/kg).


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Exposure scenarios for workers include exposure during normal operations, as well as four accidental scenarios: a worker’s hands are immersed in the spray mixture for a minute and then washed; a worker wears contaminated gloves for one hour; a worker spills the spray mixture on his/her hands, which are washed after an hour; and a worker spills the spray mixture on his/her legs, which are washed after an hour.

Following the same procedures and using the same non-site-specific data as used in the Syracuse Environmental Research Associates Inc. Risk Assessments, which provide a more conservative result, and based on site-specific pesticide-use levels, doses were calculated for potentially exposed workers for each pesticide.

Summary tables for worker exposure scenarios are available in the individual pesticide worksheets and in appendix A of this document.

3.2 Public Exposure Under normal conditions, members of the general public would not be exposed to substantial levels of these pesticides. Members of the public would generally not be in these areas during pesticide application. In addition, posting signs around treatment areas would provide warning to the public that an area is being or has recently been treated.

The proposed units are within or near parts of the Plumas National Forest used for dispersed recreation, which might include activities such as: woodcutting, hunting, camping, trail use, or gathering of plant materials. The public may pass through or near some of these areas while participating in these and other activities.

A variety of exposure scenarios can be constructed for the general public, depending on various assumptions regarding application rates, dispersion, canopy interception, and human activities. Several conservative scenarios are developed for this risk assessment. The two types of exposure scenarios developed for the general public include acute exposure, and longer-term or chronic exposure. All of the acute exposure scenarios are primarily accidental. They assume that an individual is exposed to the compound either during or shortly after its application. Specific scenarios are developed for direct spray, dermal contact with contaminated vegetation, as well as the consumption of contaminated fruit, water, and fish. Most of these scenarios should be regarded as extreme, some to the point of limited plausibility. The longer-term or chronic exposure scenarios parallel the acute exposure scenarios for the consumption of contaminated fruit, water, and fish, but are based on estimated levels of exposure for longer periods of time after application.

Direct Spray - For direct spray scenarios, it is first assumed that during ground application a naked child is sprayed directly and completely covered with pesticide. Obviously, this extremely conservative exposure scenario is virtually implausible. Another scenario involves accidental spraying of the feet and legs of a young woman. For each of these scenarios, assumptions are made regarding the surface area of the skin and the body weight.

For the scenario for dermal exposure from contaminated vegetation, it is assumed that the pesticide is sprayed at a given application rate and that an individual comes in contact with sprayed vegetation, or other contaminated surfaces at some period after the pesticide application. For these exposure scenarios, estimates of dislodgeable residue and rate of transfer from the contaminated vegetation to the surface of the skin must be made. No such data are directly available for these pesticides, and so estimation methods are used.


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Water Contamination – Water can be contaminated by pesticides from runoff, leaching from contaminated soil, drift, or from direct spill. For this risk assessment, two types of scenarios are considered: 1) acute exposure from an accidental spill, and 2) chronic exposure to pesticide in ambient water derived from application to a nearby 100-acre treatment area.

There are three acute exposure scenarios. The first scenario assumes that a young child (approximately 2 years old) consumes contaminated water shortly after an accidental spill of a field solution into a small pond. The second assumes that a small child consumes contaminated water shortly after overland flow or atmospheric drift into a stream. The third involves an adult female swimming in a contaminated pond for 1 hour. Because these scenarios involve exposure shortly after the water is contaminated, no dissipation or degradation of pesticide is assumed.

The scenario for chronic exposure from contaminated water assumes that an adult consumes contaminated, ambient water for a lifetime. Monitoring studies are available for many pesticides that allow estimation of expected concentrations in ambient water resulting from ground application over a wide area.

Table 2. Peak water contamination rates for selected pesticides

Pesticide Peak Water Contamination Rates (mg/L) Central Lower Upper

Glyphosate 0.011 0.0013 0.083

Triclopyr triethylamine salt 0.003 1E-06 0.24

3,5,6-trichloro-2-pyridinol 0.0009 1E-08 0.028

borate salt (disodium octaborate tetrahydrate) 0.041 1.2E-09 0.43

Many chemicals may be extracted from water and stored in tissues of animals or plants in the water. This process is referred to as bioconcentration. As with most absorption processes, bioconcentration depends initially on the duration of exposure but eventually reaches a steady state. Generally bioconcentration is measured as the ratio of concentration in the organism to the concentration in the water, referred to the bioconcentration factor. For both the acute and chronic exposure scenarios involving the consumption of contaminated fish, water concentrations of the pesticide that are used are identical to the concentrations use in the contaminated water scenarios. The acute exposure scenario is based on the assumption that an adult angler consumes fish taken from contaminated water shortly after an accidental spill into a pond. No dissipation or degradation of the chemical is considered. Because of the availability of well-documented information about substantial differences in the amount of caught fish consumed by the general public and Native American subsistence populations, separate exposure estimates are made for these two groups. The chronic exposure scenario is constructed in a similar manner.

Oral Exposure from Contaminated Vegetation – Under normal circumstances and in most types of applications, it is extremely unlikely that humans will consume, or otherwise place in their mouths, vegetation contaminated with these pesticides. None of the proposed applications involve crop treatment, or treatment in proximity to agricultural crops. Nonetheless, any number of scenarios could be considered, such as accidental spraying of crops, spray of edible wild vegetation such as berries, or the spraying of plants collected by Native Americans for basket weaving or medicinal use. In most instances, particularly for the chronic scenarios, treated vegetation would show signs of damage from pesticide exposure, thereby reducing the likelihood of consumption by humans.


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One of the more plausible scenarios involves the consumption of contaminated berries after treatment along a road or some other area in which wild berries grow. The two accidental exposure scenarios developed for this assessment include one scenario for acute exposure and one scenario for longer-term exposure (90-days). In both scenarios the concentration of pesticide on contaminated vegetation is estimated using a derived empirical relationship between application rate and concentration on vegetation.

Summaries tables of public exposure scenarios are available in the individual pesticide worksheets and in appendix A of this document.

Section 4 - Dose – Response Assessment In evaluating the doses received under each scenario, the doses are evaluated against the reference doses as previously discussed. If all the exposures are below the reference dose (a hazard quotient less than or equal to 1) the assumption is that a toxic response from pesticide exposure is considered negligible for the group exposed. Repeated exposure to levels below the toxic threshold does not appear to be associated with cumulative toxic effects. If any exposure exceeds the reference dose, a closer examination of various studies and exposure scenarios must be made to determine whether a toxic response is expected from the exposure. The risk assessment describes the reference doses and their bases. For those pesticides scenarios that involve doses exceeding the reference doses, it provides an analysis of various studies and further refines the risk thresholds.

Table 3 Reference doses of proposed pesticides

Pesticide Reference Dose (mg/kg/day)

Acute Chronic

Glyphosate 2.0 2.0

Triclopyr triethylamine salt 1.0 0.05

Triclopyr triethylamine salt * 0.05 0.05

3,5,6-trichloro-2-pyridinol 0.025 0.012

borate salt (disodium octaborate tetrahydrate) 3.5 0.088

* Reference dose is for exposure scenarios involving adult women of reproductive age

Section 5 - Risk Characterization A quantitative summary and narrative description of risks to workers and the public from pesticide exposure is presented in this section. The quantitative risk is expressed as the hazard quotient, which is the ratio of the estimated exposure doses to reference doses. Appendix A contains tables displaying the rates of exposure in mg/kg/day or mg/kg/event used to calculate the hazard quotients in the Syracuse Environmental Research Associates Inc. worksheets. The worksheets and the Syracuse Environmental Research Associates Inc. risk assessment contains additional information on how these values are derived. It is important to take into consideration that with any risk assessment absolute safety cannot be proven, and the absence of risk can never be demonstrated. No chemical has been studied for all possible effects, and the use of data from laboratory animals to estimate hazard to humans involves uncertainty.

5.1 Glyphosate Workers - Pesticide applicators are the individuals most likely to be exposed to a pesticide during the application process. All worker occupational exposure scenarios result in a hazard quotient of less than 1. Given the low hazard quotients for both general occupational exposure as well as accidental exposures


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scenarios, the results imply that long-term application of this herbicide can be accomplished without toxic effects. However there is some suggested information that occupational exposures to glyphosate may be associated with overt signs of toxicity (Syracuse Environmental Research Associates Inc. 2011), indicating the continued importance for use of safe handling procedures and use of personal protective equipment.

Table 4 Summary of risk characterization for workers – Glyphosate 1.2 lbs acid equivalent /acre

Scenario Receptor Hazard Quotients

Central Lower Upper

Accidental/Incidental Exposures

Contaminated Gloves, 1 min. Worker 1E-06 2E-07 2E-05

Contaminated Gloves, 1 hour Worker 9E-05 1E-05 1E-03

Spill on Hands, 1 hour Worker 2E-04 4E-05 1E-03

Spill on lower legs, 1 hour Worker 5E-04 9E-05 3E-03

General Exposures Worker 8E-03 3E-04 5E-02

Table 5 Summary of risk characterization for workers – Glyphosate 6 lbs acid equivalent per acre


Central Lower Upper






General Exposures Worker 4E-02 1E-03 0.2

General Public – For the accidental acute scenarios, none of the central exposure scenarios approached the level of concern (i.e. a hazard quotient of 1 or greater) for the typical application rates for glyphosate. However, the upper exposure level for the consumption of contaminated water by a child exceeded the level of concern or unity with a hazard quotient = 6 at 6 lbs acid equivalent /acre and a corresponding dose of 11.95 mg/kg body weight.

This exposure assessment indicates that such an event would require measures to ensure that members of the general public do not consume contaminated water. The analyzed scenario is conservative in that it entails a small child (approximately 2 years old) drinking 1.5 liters standing water from a pond shortly after an accidental spill of a field solution of 200 gallons with no dilution or pesticide decomposition.

It is highly unlikely that a young child would be exposed to a spill of field solution of this magnitude due to project design features such as designating routes of travel and mixing sites, using a closed-mixing system, requiring a separate water truck from the batch truck, and limiting the amount of tank mix used at a site. Disposing of all containers and equipment in accordance with regulations will further prevent the likelihood of water contamination.


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A contingency plan, the Herbicide Transportation, Handling, and Emergency Spill Response Plan, and a spill kit will also be on-site when pesticide treatments occur. This Plan will include reporting procedures, project safety planning, methods of clean-up of accidental spills, and information including a spill kit contents and location as noted in Forest Service Manual (FSM) 2150, Pesticide-Use Management and Coordination and Handbook (FSH) 2109.14, and Pesticide-Use Management and Coordination Handbook.

For the non-accidental acute scenarios none of the central exposure scenarios approached the level of concern for the typical application rates for glyphosate. At the upper exposure level the consumption of contaminated vegetation by an adult female is above unity (hazard quotient = 4 at 6 lbs acid equivalent/acre) with a corresponding dose of 8.1 mg/kg body weight. While this is an unacceptable level of exposure, it is far below doses that would likely result in overt signs of toxicity, and is over 35 times lower than doses where signs of toxicity were apparent (300 mg/kg). Oral doses that exceed around 300 mg/kg body weight, glyphosate may cause signs of toxicity, including decreased body weight, changes in certain biochemical parameters in blood as well as tissues, and inhibition of some enzymes (i.e., P450) involved in the metabolism of both endogenous and exogenous compounds (Syracuse Environmental Research Associates Inc. 2011).

None of the chronic scenarios were above the level of concern for any of the exposure scenarios. The highest chronic hazard quotient was for an adult female consuming vegetation at the upper exposure level with a hazard quotient equal to 0.6 at an application rate of 6 lbs acid equivalent /acre. The corresponding dose is 1.30 mg/kg body weight. The likelihood of vegetation being consumed after spraying in this project is highly unlikely due to design criteria and proposed treatment location. Project design features such as the addition of colorant to spray mixtures and signing of treatment areas should further minimize the risk of persons unknowingly eating contaminated vegetation. Additionally, to ensure members of the public do not enter treated areas during reentry intervals, applicators would remain in or near treated areas until the application solution is fully dry for all pesticides and adjuvants proposed for use in this project.

Table 6 Summary of risk characterizations for the general public – Glyphosate 1.2 lbs acid equivalent per acre


Central Lower Upper

Accidental Acute Exposures (dose in mg/kg/event)

Direct Spray of Child, whole body Child 7E-03 1E-03 5E-02

Direct Spray of Woman, feet and lower legs Adult Female 7E-04 1E-04 5E-03

Water consumption (spill) Child 0.1 1E-02 1.2

Fish consumption (spill) Adult Male 2E-03 2E-04 9E-03

Fish consumption (spill) Subsistence Populations 8E-03 9E-04 5E-02

Non-Accidental Acute Exposures (dose in mg/kg/event)

Vegetation Contact, shorts and T-shirt Adult Female 6E-04 2E-04 2E-03

Contaminated Fruit Adult Female 7E-03 3E-03 0.1

Contaminated Vegetation Adult Female 1E-01 7E-03 0.8

Swimming, one hour Adult Female 3E-09 8E-11 8E-08


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Central Lower Upper

Water consumption Child 5E-04 4E-05 6E-03

Fish consumption Adult Male 6E-06 7E-07 4E-05

Fish consumption Subsistence Populations 3E-05 3E-06 2E-04

Chronic/Longer Term Exposures (dose in mg/kg/day)

Contaminated Fruit Adult Female 1E-03 5E-04 2E-02


Water consumption Adult Male 3E-06 1E-06 1E-04



Table 7 Summary of risk characterizations for the general public – Glyphosate 6 lbs acid equivalent per acre


Central Lower Upper


Direct Spray of Child, whole body Child 2E-02 7E-03 0.3


Water consumption (spill) Child 0.4 5E-02 6


Fish consumption (spill) Subsistence Populations 2E-02 5E-03 0.2


Vegetation Contact, shorts and T-shirt Adult Female 4E-03 1E-03 9E-03

Contaminated Fruit Adult Female 4E-02 2E-02 0.6

Contaminated Vegetation Adult Female 0.5 3E-02 4






Contaminated Fruit Adult Female 6E-03 3E-03 9E-02






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5.2 Triclopyr Triethylamine Salt Data on triclopyr triethylamine salt are typically included in the dose-response assessment for triclopyr acid because these two forms of triclopyr appear to be bioequivalent in most groups of organisms (Syracuse Environmental Research Associates Inc. 2016a). The toxicity data on triclopyr acid allows for separate dose-response assessments for acute and chronic exposures.

Workers - Pesticide applicators are the individuals most likely to be exposed to a pesticide during the application process. The worker occupational exposure scenarios result in a hazard quotient of less than 1 for all scenarios except for at the upper exposure estimate for general occupational exposure (hazard quotient = 1.6) with a corresponding dose of .08 mg/kg body weight. The verbal interpretation of this hazard quotient for general exposures is somewhat ambiguous. Under typical conditions of application and at the typical application rate of 1 lb/acre, there is no indication that workers will be subject to hazardous levels of triclopyr at the central estimates of exposure. However, the upper exposure level exceeds the level of concern based on the chronic reference dose of 0.05 mg/kg/day.

While systemic toxicity is a focus of the quantitative risk characterization for triclopyr, formulations of 44.1 percent triclopyr triethylamine salt, such as Garlon 3A™, are severe eye irritants. All formulations of triclopyr triethylamine salt require the use of protective eyewear. From a practical perspective, eye irritation is probably the mostly likely effect that workers will experience during the application of triclopyr formulations; furthermore, eye irritation is the only adverse effect associated with triclopyr exposure in humans (Syracuse Environmental Research Associates Inc. 2016a).

As with all pesticide applications, potential ocular and dermal effects can and should be minimized or avoided by prudent industrial hygiene practices during and after the application of triclopyr formulations. This includes the use of safe handling procedures, and proper personal protective equipment.

Table 8. Summary of risk characterization for workers – Triclopyr triethylamine salt 1 lb acid equivalent per acre


Central Lower Upper






General Exposures Worker 0.3 9E-03 1.6

General Public – For the accidental acute scenarios, none of the exposure estimates approached the level of concern for the typical application rate of triclopyr.

For the non-accidental acute exposure scenarios, the central exposure estimate is above unity for the consumption of contaminated vegetation by an adult female (hazard quotient = 3 at 1lb acid equivalent /acre) with a corresponding dose of .16 mg/kg body weight. The corresponding upper exposure level also has a hazard quotient exceeding unity (hazard quotient = 27) with a corresponding dose of 1.35 mg/kg body weight. Additionally, the consumption of contaminated fruit by an adult female also exceeds unity at the upper exposure level (hazard quotient = 7) with a corresponding dose of 0.19 mg/kg body weight.


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There are two chronic exposure scenarios that exceed the level of concern for the upper exposure levels including the consumption of contaminated fruit and vegetation by an adult female. For the consumption of contaminated fruit the hazard quotient is 3 with a corresponding dose of 0.13 mg/kg body weight. For the consumption of contaminated vegetation by an adult female the hazard quotient equals 6 with a corresponding dose of 0.32 mg/kg body weight. However, the likelihood of fruit or vegetation being consumed after spraying in this project is unlikely in these scenarios due to design criteria and proposed treatment location.

The upper bound hazard quotients are based on very conservative exposure assumptions including the upper bound estimates of food consumption and upper bound estimates of residue rates. The use of several worst-case or at least very conservative assumptions in multiplicative models leads to assessments in which risks may be unrealistically magnified. The conservative nature of the upper bound assessments is intentional and intended to encompass risks to the Most Exposed Individual (Syracuse Environmental Research Associates Inc. 2016a).

This risk assessment uses an extreme value approach which also estimates the central estimates and lower bounds of exposure and risk. The central estimates of hazard quotients are intended to reflect exposures that are expected using typical values for consumption rates and other inputs. Lower bounds of exposures are used as best case estimates and are generally intended to represent the feasibility of risk mitigation. At an application rate of 1 lb acid equivalent/acre the lower bound hazard quotient for all of the acute and chronic scenarios are below a level of concern. For the central exposure estimates only the consumption of vegetation by an adult woman for the non-accidental exposure scenarios exceeds the level of concern. Project design features such as the addition of colorant to the spray mixture, and others mentioned in section 5.1 above, should further minimize the risk of persons unknowingly eating contaminated vegetation or fruit.

Table 9. Summary of risk characterizations for the general public – Triclopyr triethylamine salt 1 lb acid equivalent per acre


Central Lower Upper



Direct Spray of Woman, feet and lower legs Adult Female 4E-02 1E-02 0.2

Water consumption (spill) Child 0.2 2E-02 0.7




Vegetation Contact, shorts and T-shirt Adult Female 4E-02 2E-02 0.1

Contaminated Fruit Adult Female 0.2 0.1 4

Contaminated Vegetation Adult Female 3 0.2 27






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Central Lower Upper

Chronic/Longer Term Exposures (dose in mg/kg/event)

Contaminated Fruit Adult Female 9E-02 3E-02 3





5.3 3,5,6-trichloro-2-pyridinol General Public – The reference doses used for the 3,5,6-trichloro-2-pyridinol exposure scenarios are lower than those for triclopyr triethylamine salt for both the acute and chronic exposure scenarios. Exposure assessments for 3,5,6-trichloro-2-pyridinol are limited to the general public and do not include worker exposure scenarios, or assessments involving direct spray or vegetation contact. This is because toxic 3,5,6-trichloro-2-pyridinol exposure occurs from longer term exposure since it is an environmental metabolite.

For the non-accidental acute scenarios all of the central estimates are below the level of concern except for the consumption of contaminated vegetation by an adult female which marginally exceeds the level of concern (hazard quotient = 1.8 at an application rate of 1 lb acid equivalent/acre) with a corresponding dose of 0.05 mg/kg body weight. The upper exposure level for the consumption of vegetation also surpasses the level of concern (hazard quotient = 15 at an application rate of 1 lb acid equivalent/acre) with a corresponding does of 0.38 mg/kg body weight. Similarly, the consumption of fruit by an adult female is also above unity at the upper exposure level (hazard quotient = 2 at an application rate of 1 lb acid equivalent /acre) with a corresponding dose of 0.053 mg/kg body weight.

Similar to the non-accidental acute exposure scenarios the chronic scenarios of concern involve the consumption of vegetation and fruit by an adult female. At the central exposure estimate the concern is marginal for an adult female eating contaminated vegetation (hazard quotient = 1 at an application rate of 1 lb acid equivalent /acre) with a corresponding dose of 0.01 mg/kg hazard quotient. However, the upper exposure level for the consumption of contaminated vegetation is above unity (hazard quotient = 19 at an application rate of 1 lb acid equivalent /acre) with a corresponding dose of 0.23 mg/kg body weight, The consumption of contaminated fruit also exceeds the level of concern at the upper exposure level (hazard quotient = 4 at an application rate of 1 lb acid equivalent /acre) with a dose of 0.012 mg/kg body weight.

Relative to the risks associated with the consumption of contaminated fruit or vegetation, risks associated with other exposure scenarios are marginal. As noted in the above risk characterizations, the likelihood of fruit or vegetation being consumed unknowingly after spraying in this project is unlikely in these scenarios due to application of project design features.


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Table 10. Summary of risk characterizations for the general public – 3,5,6-trichloro-2-pyridinol 1 lb acid equivalent per acre


Central Lower Upper


Direct Spray of Child, whole body Child No exposure assessment.

Direct Spray of Woman, feet and lower legs Adult Female No exposure assessment.

Water consumption (spill) Child 3E-02 1E-03 0.2


Fish consumption (spill) Subsistence Populations 6E-02 1E-02 0.2


Vegetation Contact, shorts and T-shirt Adult Female No exposure assessment.

Contaminated Fruit Adult Female 0.1 6E-02 2

Contaminated Vegetation Adult Female 1.8 0.1 15


Water consumption Child 3E-03 2E-08 0.1




Contaminated Fruit Adult Female 0.2 8E-02 4




5.4 Borate Salt (Disodium Octaborate Tetrahydrate) Borate salts are rapidly converted to boric acid under conditions typically found in the environment. At physiological pH and in most surface waters, most organisms are exposed primarily to boric acid. Therefore, information on boric acid is reviewed as appropriate and used as surrogate data in this risk assessment for borate salt (disodium octaborate tetrahydrate) (Syracuse Environmental Research Associates Inc. 2016b).

Workers - All worker occupational exposures for the central, lower and upper exposure levels result in a hazard quotient of less than 1. Given the low hazard quotients for both general occupational exposures as well as accidental exposures, the results imply that long-term employment applying this fungicide can be accomplished without toxic effects.

As previously discussed, these upper limits of exposure are constructed using the highest anticipated application rate, the highest anticipated number of acres treated per day, and the upper limit of the occupational exposure rate. If any of these conservative assumptions were modified the hazard quotients would drop substantially. The verbal interpretation of this quantitative characterization of risk is that even


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under the most conservative set of exposure assumptions, workers would not be exposed to levels of boric acid that are regarded as unacceptable. Protective eyewear is recommended when handling borate salt (disodium octaborate tetrahydrate) which has been found to cause mild eye irritation in rabbits (Nisus 2009).

Table 11. Summary of risk characterization for workers – borate salt (disodium octaborate tetrahydrate) 0.5 lbs per acre


Central Lower Upper






General Exposures

Liquid Application, Standard Worker 2E-04 1E-05 2E-03

Liquid Application, Backpack, PHED Worker 3E-04 6E-05 8E-04

Liquid Application, HED, PHED Worker 1E-03 5E-04 3E-03

*This is a specially developed template for workers applying borax as a liquid or granular in stump applications. Designed for 2016 risk assessment on Cellu-Treat®.

General Public –None of the accidental acute and chronic exposure scenarios approached the level of concern at an application rate of 0.5 lbs/acre. Scenarios associated with the consumption of contaminated vegetation are not included for the borate risk characterization because these compounds are applied directly to tree stumps and the likelihood of contaminating edible vegetation is minimal. Although Cellu-treat® is not applied in residential areas, it is applied in forested areas that may be used by members of the general public such as in or near recreational areas like campgrounds and picnic areas. Conversely, members of the general public are less likely to be exposed to borates in stump applications made in remote areas; however, in either instance it is highly unlikely that a member of the public would be exposed to either freshly treated stumps, or water containing Cellu-treat® since it would be applied to freshly cut tree stumps only during harvesting operations when public access to the site would be restricted, and would not be applied within riparian conservation area buffers. Additional mitigation measures such as restricting application on weekends or holidays would also be implemented to minimize impacts to recreation.

Table 12. Summary of risk characterizations for the general public – borate salt (disodium octaborate tetrahydrate) 0.5 lbs per acre


Central Lower Upper




Water consumption (spill) Child 5E-03 6E-04 2E-02



20


Central Lower Upper




Contaminated Fruit Adult Female No exposure assessment.

Contaminated Vegetation Adult Female No exposure assessment.











5.5 Sensitive Individuals The 1996 Food Quality Protection Act requires that the EPA evaluate risks with an additional 10 times safety factor based on data uncertainty or risks to certain age/sex groups groupings. The most sensitive subgroup for exposure to glyphosate and glyphosate formulations are pregnant women and developing fetuses. Since the reference doses for glyphosate used in the current Syracuse Environmental Research Associates Inc. (2011) risk assessment is based on a developmental study, the sensitivity of this group is explicitly addressed. A separate concern for the risk characterization of glyphosate involves genotoxic effects. There is research that suggests that sprays of glyphosate formulations mixed with surfactants may be associated with genotoxic effects—i.e., micronuclei and binucleated cells with micronuclei. Whether or not these studies represent exposures that are relevant to applications in the United States is not clear (Syracuse Environmental Research Associates Inc. 2011).

Triclopyr is associated with adverse reproductive effects in experimental mammals. While there are no epidemiology studies supporting a link between exposure to triclopyr and adverse reproductive outcomes in humans, reproductive toxicity is an endpoint of particular concern in Forest Service risk assessments (Syracuse Environmental Research Associates Inc. 2016a). Since the chronic reference dose is based on reproductive effects to women of reproductive age the sensitivity of this group is explicitly addressed. The chronic reference dose is also used as the acute reference dose for this group because of concerns for the reproductive and developmental toxicity of triclopyr.

Given some of the high hazard quotients for both acute and chronic scenarios, particularly for members of the general public who might consume contaminated vegetation or fruit for both the acute and chronic scenarios, the potential for adverse effects in adult females is an obvious concern. As discussed in Syracuse Environmental Research Associates Inc. (2016a), no reports of frank adverse effects in workers (male or female) applying any triclopyr formulation are included in the available literature. In the occupational exposure studies on terrestrial applications of triclopyr in Syracuse Environmental Research Associates Inc. (2016a) no signs of even mild toxicity in workers are reported in a study by Gosselin et al.


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(2005) or in any of the other worker exposure studies. All of these studies involve male rather than female workers; however, there is no basis for asserting that frank adverse effects in female workers would be expected at doses substantially below those which might be associated with frank adverse effects in male workers.

The most reasonable interpretation of the above risk characterization for female workers applying triclopyr as well as females in the general public who might consume food items contaminated with triclopyr or 3,5,6-trichloro-2-pyridinol is that the exposure assessments clearly indicate that some females could be exposed to triclopyr or 3,5,6-trichloro-2-pyridinol levels that are clearly of concern – i.e., above the reference dose. Based on the available developmental studies on triclopyr as well as human experience with triclopyr, it is far less certain that adverse reproductive outcomes due to the toxicity of triclopyr would occur. Epidemiology studies on women of childbearing age with documented exposures to triclopyr could be useful in better assessing the potential risks of adverse reproductive outcomes (Syracuse Environmental Research Associates Inc. 2016a).

Triclopyr is excreted primarily by the kidney. Individuals with kidney disease could have an impaired ability to excrete triclopyr. No reports, however, linking triclopyr exposures with adverse effects in individuals with kidney disease were identified in the available literature (Syracuse Environmental Research Associates Inc. 2016a).

Some individuals report a high degree of sensitivity to multiple chemicals, resulting in a broad-spectrum of effects, many of which are similar to allergic reactions. This condition is generally referred to as Multiple Chemical Sensitivity (e.g., Agency for Toxic Substances and Disease Registry 1995, as referenced in Syracuse Environmental Research Associates Inc. 2016a). There are no reports in the literature associating exposures to triclopyr with adverse effects in individuals who report having Multiple Chemical Sensitivity (Syracuse Environmental Research Associates Inc. 2016a).

The more recent assessment of boron by the Agency for Toxic Substances and Disease Registry in 2010 does not identify subgroups likely to be particularly more sensitive to borates:

No data were located identifying a population that is unusually susceptible to boron toxicity. Case reports in humans suggest that large variability exists with the human population to the lethal effect of boron. However, there are no data to suggest which segment of the population is more susceptible to boron (Agency for Toxic Substances and Disease Registry 2010, p. 103, as referenced in Syracuse Environmental Research Associates Inc. 2016b).

The major concern with exposure to borates involves reproductive effects including testicular atrophy, therefore the longer-term surrogate reference dose is based on testicular atrophy. The uncertainty factors used by EPA (U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division 2015, p. 11, as referenced in Syracuse Environmental Research Associates Inc. 2016b) and incorporated into the current risk assessment are intended to accommodate sensitive individuals in the human population.

5.6 Synergistic Effects Synergistic effects (multiplicative) are those effects resulting from exposure to a combination of two or more chemicals that are greater than the sum of the effects of each chemical alone (additive). In USDA Forest Service (1989) (pages 4-111 to 4-114) provides a detailed discussion of synergistic effects. Instances of chemical combinations that cause synergistic effects are relatively rare.

Surfactants by nature are intended to increase the effect of pesticide by increasing the amount of pesticide that is in contact with the target. Current data indicates a lack of synergistic effects between surfactants


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and pesticides. Increased absorption would require physical effect to the skin which is not likely to result from the addition of non-ionic surfactants (USDA Forest Service 2002/2007; and USDA Forest Service 2003).

Based on the very low exposure rates estimated for this project with the pesticides individually any synergistic or additive effects are expected to be insignificant. While it is plausible that for glyphosate some mechanisms of interaction could occur with other chemicals, it would likely be relevant only at very high doses, substantially above proposed exposure levels (Syracuse Environmental Research Associates Inc. 2011). No information is available on the interactions of aminopyralid with other compounds and most inferences that can be made are speculative.

Many formulations of triclopyr triethylamine salt require the use of surfactants, and some surfactants may be hazardous. Triclopyr is a relatively typical weak-acid auxin herbicide. Herbicides such as aminopyralid, clopyralid, and picloram are similar with respect to their structure, pharmacokinetics, and toxicity. It is reasonable to anticipate that exposure to triclopyr and other weak acid herbicides would result in essentially additive risks (Syracuse Environmental Research Associates Inc. 2016a).

As discussed in detail in the Syracuse Environmental Research Associates Inc. (2016a) risk assessment, triclopyr will be metabolized to 3,5,6-trichloro-2-pyridinol. Exposures to 3,5,6-trichloro-2-pyridinol will be associated with any use of triclopyr in Forest Service programs. The impact of 3,5,6-trichloro-2-pyridinol is considered quantitatively in the human health risk assessment and is considered further in the ecological risk assessment (Syracuse Environmental Research Associates Inc. 2016a).

There is no evidence in the available literature that borates will synergize adverse effects of other agents. The borate formulation considered in this risk assessment does not contain inert components. In addition, the borates are not applied in combination with other products or additives. (Syracuse Environmental Research Associates Inc. 2016b).

5.7 Cumulative Effects Cumulative effects may involve either repeated exposures to an individual agent or simultaneous exposures to the agent of concern and other agents that may cause the same effect or effects by the same or a similar mode of action.

It is possible and even likely that some individuals will be exposed to multiple sources of pesticides as a result of Forest Service programs, or that individuals could be exposed to additional pesticides from use on adjacent private timberlands, or home use by a worker or member of the general public.

The EPA has completed tier 1 testing on glyphosate and “Based on weight of evidence considerations, mammalian or wildlife EDSP Tier 2 testing is not recommended for glyphosate since there was no convincing evidence of potential interaction with the estrogen, androgen or thyroid pathways” (U.S. Environmental Protection Agency 2015, p. 2).

While it is possible that workers and members of the public could travel to other areas and be exposed to pesticides, pesticide use near the project area is more likely to be the result of cumulative exposure. Because of the size of the Moonlight fire and the impacts to neighboring private industrial timber land, it is expected that reforestation efforts on private lands will include the use of pesticides, including Velpar and other formulations not proposed for use on National Forest system lands.

Additional sources of exposure are also expected to occur from pesticide use on National Forest Lands for example with noxious weed abatement programs and FERC hydropower facility/infrastructure maintenance. Pesticide use on both the National Forest and on private lands is regulated by the California


23

Department of Pesticide Regulation and the local county agricultural commissioners in the county where pesticide is applied.

The main potential for exposure from projects on the Plumas National Forest involving the pesticides proposed for use on this project is continuing treatment of noxious weeds on the Plumas National Forest, primarily using glyphosate. Hasten, R-11, and Syl-Tac are the surfactants most commonly used in glyphosate applications. Additional pesticides currently being used on the Plumas National Forest also include aminopyralid and imazapyr for noxious weed abatement and FERC hydropower facility/infrastructure maintenance.

This risk assessment and those used to develop this risk assessment specifically consider the effect of repeated exposure in that the chronic (derived) reference dose is used as an index of acceptable exposure. Repeated exposure to levels below the toxic threshold does not appear to be associated with cumulative toxic effects when glyphosate is applied at the proposed application rates. Since glyphosate persists in the environment for a relatively short time (generally less than 1 year), does not bioaccumulate, and is rapidly eliminated from the body, doses from re-treatments in subsequent years are not expected to have additive effects.

In 1991, U.S. EPA concluded that glyphosate should be classified as a Group E (evidence of non-carcinogenicity for humans) based on a lack of convincing carcinogenicity evidence and considering the criteria in EPA Guidelines for classifying a carcinogen.

Recently, the International Agency for Research on Cancer (IARC) Monograph Working Group determined that glyphosate should be classified as “probably carcinogenic to humans” (Guyton et al. 2015). This recent decision was based on a review of existing studies and not on new research which found limited evidence in humans for the carcinogenicity of glyphosate. Some case-control studies of occupational exposure in the USA, Canada, and Sweden reported increased risks for non-Hodgkin lymphoma after adjustment for other pesticides.

The USDA Forest Service human health and ecological risk assessment for glyphosate (Syracuse Environmental Research Associates Inc. 2011), includes a lengthy discussion of the mutagenic and carcinogenic potential of glyphosate including non-Hodgkin’s lymphoma. Some of the key references used in Guyton et al. (2015) and another recent, but more in-depth review conducted by Schinasi and Leon (2014) are discussed in the Syracuse Environmental Research Associates Inc. glyphosate risk assessment (2011). The risk assessment concludes (page 70):

The nature of the available epidemiology data on glyphosate is addressed in the U.S. EPA/OPP (2002a) assessment:

This type of epidemiologic evaluation does not establish a definitive link to cancer. Furthermore, this information has limitations because it is based solely on unverified recollection of exposure to glyphosate-based herbicides.

Based on an evaluation of the available animal studies as well as epidemiology studies, U.S. EPA/OPP (2002a, p. 60943) classifies the carcinogenic potential of glyphosate as Group E, No Evidence of Carcinogenicity. Given the marginal mutagenic activity of glyphosate (Section 3.1.10.1), the failure of several chronic feeding studies to demonstrate a dose-response relationship for carcinogenicity, and the limitations in the available epidemiology studies on glyphosate, the Group E classification in U.S. EPA/OPP (1993, 2002a) appears to be reasonable.


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It has been the USDA Forest Service practice to defer to the U.S. EPA unless there is a compelling reason to do otherwise. At this point, there is not yet a compelling reason to adopt the International Agency for Research on Cancer’s classification since all the technical details are not yet available from the International Agency for Research on Cancer and since the U.S. EPA’s and our analyses would indicate a different conclusion. As stated, a new risk assessment from the U.S. EPA is expected in the near future and this will undoubtedly consider the International Agency for Research on Cancer’s classification. If the US EPA accepts the International Agency for Research on Cancer recommendation, then the USDA Forest Service would consider an update to the glyphosate risk assessment and for purposes of existing NEPA documents, such a reclassification would be considered ‘new information’.

Triclopyr triethylamine salt does not persist in the environment and has a low potential for bioconcentration in fish. The triethylamine salt of triclopyr will dissociate essentially instantaneously in aqueous solutions to triclopyr acid and trimethylamine (Syracuse Environmental Research Associates Inc. 2016a). Triclopy acid has a relatively low potential for bioconcentration. Research indicates that triclopyr acid has an estimated half-time of 426 days in water and approximately 59 (24-143) days in soil, with the water half-time being a conservative estimate (Syracuse Environmental Research Associates Inc. 2016a). Following oral exposure, triclopyr is absorbed and excreted relatively rapidly from the human body (Syracuse Environmental Research Associates Inc. 2016a).

Overt toxic effects in workers do not appear to be likely with repeated application of triclopyr at the lower and central exposure levels. The upper exposure level does however, exceed the level of concern based on the chronic reference dose of 0.05 mg/kg/day. As summarized in Section 3.1 in Syracuse Environmental Research Associates Inc. (2016a), there are no epidemiology studies or case reports which suggest that systemic toxic effects are associated with occupational or even accidental exposures to any form of triclopyr; furthermore, no poisoning reports involving any form of triclopyr are documented in the reasonably comprehensive summary of human case reports on pesticide exposures by Hayes (1982, as referenced in Syracuse Environmental Research Associates Inc. 2016a). Given that triclopyr is proposed for use as a follow-up spot treatment for the Moonlight project, it is not anticipated to have additive effects.

A detailed summary of the mutagenicity studies on triclopyr most of which indicate no mutagenic activity is provided in Syracuse Environmental Research Associates Inc. (2016a). The EPA has determined that the evidence for carcinogenity for triclopyr is marginal based on current research and has classified the chemical as a Group D chemical (not classifiable to human carcinogenity). This position is articulated briefly in U.S. Environmental Protection Agency, Office of Pesticide Programs (1998), and because of the importance of this decision to the risk assessment, the position is worth quoting directly:

As a result of the August 9, 1995 meeting of the Agency's Carcinogenicity Peer Review Committee (CPRC), triclopyr was classified as a Group D chemical (not classifiable as to human carcinogenicity). This decision was based on increases in mammary tumors in both the female rat and mouse, and adrenal pheochromocytomas in the male rat, which the majority of the CPRC believed to be only marginal. Overall the majority of the CPRC felt that the animal evidence was marginal (not entirely negative, but yet not convincing). Therefore, the consensus of the CPRC was to classify triclopyr as a Group D chemical, based on what was considered only marginal response and the absence of additional support from structural analogs or genotoxicity. (U.S. EPA/OPP 1998, p. 18, as referenced in SERA 2016a).

The primary metabolite of triclopyr 3,5,6-trichloro-2-pyridinol is formed in all relevant media, as a metabolite in plants, soil and water. 3,5,6-trichloro-2-pyridinol is also the primary metabolite of an insecticide called chlorpyrifos. Chlorpyrifos is an organophosphate insecticide that acts by inhibition of cholinesterase (U.S. Environmental Protection Agency, Office of Pesticide Programs 2001; U.S. EPA 1998, 2002b, as referenced in Syracuse Environmental Research Associates Inc. 2016a)


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The U.S. EPA (1998, 2002, as referenced in Syracuse Environmental Research Associates Inc. 2016a) has conducted extensive analyses of dietary exposure to 3,5,6-trichloro-2-pyridinol from the use of triclopyr as well as the aggregate risks from exposure to 3,5,6-trichloro-2-pyridinol from the use of both triclopyr and chlorpyrifos. While the dietary exposures estimated by the EPA are substantially below a level of concern, the EPA risk assessment does not consider the types of oral exposures routinely considered in Forest Service risk assessments (Syracuse Environmental Research Associates Inc. 2016a).

This EPA risk assessment is based primarily on their assessments for dietary and drinking water which does not specifically address potential exposures from forestry applications. In forestry applications, the primary concern would be the potential for eating contaminated food products e.g. fruit or vegetation, and the formation of 3,5,6-trichloro-2-pyridinol as a soil metabolite. 3,5,6-trichloro-2-pyridinol is more persistent than triclopyr in soil with a half-time of 149 (81-242) days; however, it is less persistent than triclopyr in water with an estimated halftime of 6 days (Syracuse Environmental Research Associates Inc. 2016a). Bioconcentration studies on 3,5,6-trichloro-2-pyridinol are not available. For the Syracuse Environmental Research Associates Inc. (2016a) risk assessment bioconcentration factors were assumed to be the same as triclopyr acid based on available data. Because 3,5,6-trichloro-2-pyridinol is more toxic than triclopyr, the hazards associated with the consumption of fruit or vegetation contaminated with 3,5,6-trichloro-2-pyridinol cannot be disregarded (Syracuse Environmental Research Associates Inc. 2016a).

A major limitation in assessing potential exposures to 3,5,6-trichloro-2-pyridinol in fruit or vegetation, however, is the lack of information on the kinetics of the formation and degradation/dissipation of 3,5,6-trichloro-2-pyridinol in plant tissue. There is some research examining the half-lives of 3,5,6-trichloro-2-pyridinol in grass and fruit. In the extensive review of the environmental fate of 3,5,6-trichloro-2-pyridinol by Knuteson (1999), there is no information on the rates of formation and degradation of 3,5,6-trichloro-2-pyridinol in plant tissue following applications of triclopyr (Syracuse Environmental Research Associates Inc. 2016a). Similarly, no information on these rates has been encountered in the assessments by U.S. Environmental Protection Agency, Office of Pesticide Programs or in open literature reviews.

Other studies summarized in Ganapathy (1997) report no or very low residues of 3,5,6-trichloro-2-pyridinol following applications of triclopyr. In the absence of more detailed information on these studies (e.g., monitoring schedule), however, these other studies cannot be fully interpreted, except to note that they report low concentrations of 3,5,6-trichloro-2-pyridinol in vegetation. As discussed below, low 3,5,6-trichloro-2-pyridinol concentrations in vegetation would be expected in some cases, depending on the degradation of kinetics for triclopyr and 3,5,6-trichloro-2-pyridinol under the conditions of a particular study. The only reported half-life for 3,5,6-trichloro-2-pyridinol in vegetation is 10 days, a value reported in the review by Ganapathy (1997) from an unpublished study (DowElanco Data package 51566-006) on residues in grass (Ganapathy 1997, pp. 12-13). This half-life does not differ substantially from the reported half-lives for triclopyr in plants. Results from this study suggest that the exposure assessment for 3,5,6-trichloro-2-pyridinol in vegetation may be somewhat conservative, but not overly so.

In the absence of more detailed data on the kinetics of 3,5,6-trichloro-2-pyridinol in plants, the Syracuse Environmental Research Associates Inc. risk assessment from which this risk assessment is based assumes that 3,5,6-trichloro-2-pyridinol half-times are comparable to those of triclopyr—i.e., 6.2 (2.6 – 15) days in vegetation and 27 (16.5-73) days in fruit (Syracuse Environmental Research Associates Inc. 2016a). This half-life does not differ substantially from the reported half-lives for triclopyr in plants, however it is not the most conservative approach that could be taken for this assessment. While this more conservative approach would modestly increase exposure and the subsequent assessment of risk, the risks associated with 3,5,6-trichloro-2-pyridinol residues on contaminated vegetation are evident, as detailed further in the Syracuse Environmental Research Associates Inc. (2016a) risk assessment. In addition, taking the more conservative approach would disregard the information from Ganapathy (1997). The


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Ganapathy (1997) review is from the Environmental Monitoring and Pest Management Branch of the Department of Pesticide Regulation/California EPA. This is a highly credible organization and it would not be appropriate for the current risk assessment to disregard the review from Ganapathy (1997, as referenced in Syracuse Environmental Research Associates Inc. 2016a).

The high hazard quotients for the chronic exposure scenarios for the consumption of vegetation and fruit contaminated with triclopyr acid and 3,5,6-trichloro-2-pyridinol by an adult women are clearly a concern; however, it is important to take into consideration that applications of triclopyr associated with Forest Service programs will not involve crop treatment. Under normal circumstances and in most types of applications, it is highly unlikely that humans will unknowingly consume substantial amounts of vegetation or fruit contaminated with triclopyr due to project design features such as the addition of colorant to the spray mixture and signing of treatment areas. Nonetheless, any number of accidental or incidental scenarios could be developed involving either spraying of crops, gardens, or edible wild vegetation. Again, in most instances and particularly for longer-term scenarios, treated vegetation would probably show signs of damage from exposure to triclopyr, thereby reducing the likelihood of consumption which might lead to significant levels of human exposure (Syracuse Environmental Research Associates Inc. 2016a).

As previously mentioned triclopyr acid will be applied in a limited capacity as a follow-up spot treatment in the Moonlight project. Mitigation measures will also be applied to further reduce the risk of exposure to the public to triclopyr acid and 3,5,6-trichloro-2-pyridinol during project implementation. Additional inputs of triclopyr, 3,5,6-trichloro-2-pyridinol and chlorpyrifos from agricultural and other commercial uses on adjacent private lands are anticipated to be relatively minor compared with usage of these chemicals elsewhere in California where agriculture is more extensively practiced, and not anticipated to have additive effects.

The most recent EPA human health risk assessment does not make a determination of whether other pesticides may have cumulative effects with borates:

Unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as to boric acid and its sodium salts and any other substances and boric acid/sodium salts do not appear to produce a toxic metabolite produced by other substances. For the purposes of this tolerance action, therefore, EPA has not assumed that boric acid/sodium salts have a common mechanism of toxicity with other substances. (U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division 2015, p. 54, as referenced in Syracuse Environmental Research Associates Inc. 2016b).

Cumulative effects associated with the contribution of the Forest Service uses of borates to normal background levels of borates are a consideration since boron is a naturally occurring element (Syracuse Environmental Research Associates Inc. 2016b). However, based on the recent Syracuse Environmental Research Associates Inc. risk assessment (2016b), the uses of borates in Forest Service programs will not contribute substantially to normal background levels of exposure, as reflected in the extraordinarily lower hazard quotients for most exposure scenarios when borates are applied at the typical application rate. The only exceptions involve workers involved in dry applications of Sporax® (not proposed for use in the Moonlight project), and the accidental exposure scenario for the consumption of borax by a child. In both of these cases, background exposures to borax are much lower than estimated exposures for the worker or the child. Thus, a specific consideration of background levels of exposure would not affect the risk characterization. It should be noted that the explicit doses reported in all of the toxicity studies as well as human incidents also involve implicit and unquantified background exposures to boron (Syracuse Environmental Research Associates Inc. 2016b).


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Standard chronic carcinogenicity studies are available in rats (MRID 40692309) and mice (MRID 41863101). No carcinogenic responses were observed in either bioassay. In addition, standard in vitro mutagenicity bioassays required by the EPA are also negative (Syracuse Environmental Research Associates Inc. 2016b). Based on a the data, the most recent human health risk assessment from the EPA has indicated that boric acid and associated borates are classified as “Not Likely to be Carcinogenic to Humans” (U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division 2015a, p. 5 , as referenced in Syracuse Environmental Research Associates Inc. 2016b).

For all pesticides proposed for use in this project pesticide application would be consistent with the Forest Service Pesticide Use Policy, and would be in compliance with state and federal regulations. Additionally, it would follow USDA Forest Service Region 5 Best Management Practices for Water Quality and Vegetation Manipulation and the USDA Forest Service Region 5 supplement No. 2100-95-1 to 2150 on Pesticide-Use Management and Coordination. Appropriate monitoring protocols will also be used to ensure the proposed pesticides are applied according to requirements and label specifications. Additional project design criteria is listed in the Moonlight Environmental Assessment.


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References Agency for Toxic Substances and Disease Registry (ATSDR). 2010. Toxicological Profile for Boron.

Available at: http://www.atsdr.cdc.gov/ToxProfiles/tp26.pdf .

Borrecco, J., Neisess, J. 1991. Risk assessment for the impurities 2-butoxyethanol and 1,4-dioxane found in Garlon 4 and Roundup herbicide formulations. Pacific Southwest Region, Forest Pest Management. Report No. R91-2. 33 pages.

Ganapathy, C. 1997. Environmental Fate of Triclopyr. California Department of Pesticide Regulation. Environmental Monitoring & Pest Management Branch. Report dated Jan. 2, 1997. Available at: http://www.cdpr.ca.gov/docs/emon/pubs/fatememo/triclopyr.pdf.

Gosselin N.H., Brunet R.C., Carrier G., and A. Dosso. 2005. Worker Exposures to Triclopyr: Risk Assessment Through Measurements in Urine Samples. Ann Occup Hyg. 49(5):415-22.

Guyton, K.Z., et al. 2015. Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate. Lancet Oncology. Published online March 20, 2015. http://www.thelancet.com/pdfs/journals/lanonc/PIIS1470-2045%2815%2970134-8.pdf. Accessed online on 07/14/15.

Hayes WJ Jr. 1982. Pesticides studied in man. Baltimore/London: Williams & Wilkins, 672 pp.

Knuteson J. 1999. Review of Environmental Fate of 3,5,6-Trichloro-2-pyridinol. (TCP): Laboratory, Terrestrial and Aquatic Field Studies: Lab Project Number: GH-C 4875. Unpublished study prepared by Dow AgroSciences LLC. 75 p. MRID 44766301. DowAgro Document Code: 67447.

Mirvish SS. 1995. Role of N-nitroso compounds (NOC) and N-nitrosation in etiology of gastric, esophageal, nasopharyngeal and bladder cancer and contribution to cancer of known exposures to NOC. Cancer Lett. 93(1): 17-48.

Mizell M. Lomax L. 1988. Garlon 3A (Triclopyr as Triethylamine Salt): Acute Oral Toxicity Study in Fischer 344 Rats: Lab Project Number: M-003724-009A. Unpublished study prepared by The Dow Chemical Co. 28 p. MRID 41443301.

National Research Council. 1983. Risk Assessment in the Federal Government: Managing the Process. The National Academies Press. Washington, DC.

Nisus (Nisus Corporation). 2009. DOT Cellu-Treat® Wood Preservative. Material Safety Data Sheet. Issued 8/2001, Updated 1/2009. Available at: http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5329557.pdf.

Schinasi, Leah and Maria E. Leon. 2014. Non-Hodgkin lymphoma and occupational exposure to agricultural pesticide chemical groups and active ingredients: a systematic review and meta-analysis. International Journal Environmental Research and Public Health. 2014 (11) 4449-4527.

Syracuse Environmental Research Associates Inc. (SERA). 1997a. Use and assessment of Marker Dyes used with Herbicides. December 21, 1997. Sera TR 96-21-07-03b. Fayetteville, New York. 47 pp.

Syracuse Environmental Research Associates Inc. 1997b. Effects of Surfactants on the Toxicity of Glyphosate, with Specific Reference to Rodeo. SERA TR97-206-1b. 32 pages.

http://www.cdpr.ca.gov/docs/emon/pubs/fatememo/triclopyr.pdf

http://www.thelancet.com/pdfs/journals/lanonc/PIIS1470-2045%2815%2970134-8.pdf


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Syracuse Environmental Research Associates Inc. 2010. Appendices to Glyphosate Human Health and Ecological Risk Assessment – Final Report. November 29, 2010. SERA TR-052-22-03a-APP. 123 pages.

Syracuse Environmental Research Associates Inc. 2011. Glyphosate Human Health and Ecological Risk Assessment – Final Report. March 25, 2011. SERA TR-052-22-03b. Manlius, New York. 336 pages.

Syracuse Environmental Research Associates Inc. 2016a. Triclopyr Human Health and Ecological Risk Assessment – Corrected Final Report. July 9, 2016. SERA TR0-052-25-03c. Manilus, New York. 251 pages.

Syracuse Environmental Research Associates Inc. 2016b. Sporax and Cellu-treat (Selected Borate Salts) Human Health and Ecological Risk Assessment – Final Report. October 17, 2016. SERA TR-056-15-03c. Manilus, New York. 236 pages.

USDA Forest Service. 1989. Final Environmental Impact Statement - Vegetation Management for Reforestation. USDA Forest Service, Pacific Southwest Region. Vallejo, California.

USDA Forest Service. 2000. Consideration of Cancer Risk with Colorfast Purple Dye. Unpublished report written by David Bakke, Pacific Southwest Regional Pesticide-Use Specialist. 1 page.

USDA Forest Service. 2003. Human and Ecological Risk Assessment of Nonylphenol Polyethoxylate-based (NPE) Surfactants in Forest Service Herbicide Applications. Unpublished report written by David Bakke, Pacific Southwest Regional Pesticide-Use Specialist. 110 pages.

USDA Forest Service. 2002 and 2007 update. Analysis of issues surrounding the use of spray adjuvants with herbicides. Unpublished report written by David Bakke, Pacific Southwest Regional Pesticide-Use Specialist. 61 pages.

U.S. Environmental Protection Agency (U.S. EPA). 1986. Guidelines for the health risk assessment of chemical mixtures. Federal Register 51: 1850: 3414-34025. September 24, 1986.

U.S. Environmental Protection Agency. 2015. EDSP: Weight Of Evidence Analysis Of Potential Interaction With The Estrogen, Androgen Or Thyroid Pathways. Office Of Pesticide Programs, Office Of Science Coordination And Policy, U.S. Environmental Protection Agency

U.S. Environmental Protection Agency, Office of Pesticide Programs (OPP). 1993. Health Effects Division's Chapter of the Reregistration Eligibility Document (RED) for Glyphosate, Case #0178. Document dated Jan 15, 1993.

U.S. Environmental Protection Agency, Office of Pesticide Programs. 1998. Reregistration Eligibility Decision (RED): Triclopyr. Available at: http://www.epa.gov/pesticides/reregistration/status_page_t.htm.

U.S. Environmental Protection Agency, Office of Pesticide Programs (U.S. Environmental Protection Agency/ Office of Pesticide Programs). Ecological Risk Assessor Orientation Package. Draft Version August 2001. Prepared by Brian Montague, Ecological Fate and Effects Division (EFED), U.S. EPA, Office of Pesticide Programs, Environmental Fate and Effects Division.

U.S. Environmental Protection Agency, Office of Pesticide Programs 2002a. Glyphosate: Pesticide Tolerances, 40 CFR Part 180. Federal Register. 67(188): 60934-60950.

http://www.epa.gov/pesticides/reregistration/status_page_t.htm


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U.S. Environmental Protection Agency, Office of Pesticide Programs 2002b. EPA: Federal Register: Triclopyr; Pesticide Tolerance. Federal Register. 67(181): 58712-58725.

U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and Effects Division (EFED). 2015. Preliminary Environmental Fate and Ecological Risk Assessment for the Registration Review of Boric Acid and Sodium Borate Salts. Document dated November 25, 2015. EPA-HQ-OPP-2009-0306-0021.

World Health Organization. 1988. IARC Monographs on the Evaluation of Carcinogenic Risk to Humans: Alcohol Drinking. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, Lyon, France. International Agency for Research on Cancer, World Health Organization, Geneva Switzerland. pp. 122-125.


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Appendix A – Exposure Scenarios This appendix contains summary tables for exposure scenarios for workers and the general public used to derive the hazard quotients for each pesticide rate proposed for use and a more toxic formulation to account for addition of surfactants to the proposed pesticide.

Worker Exposure Scenarios – Glyphosate

Table 13. Summary of worker exposure scenarios – Glyphosate 1.2 lbs acid equivalent/acre

Scenario Receptor mg/kg/day or mg/kg/event

Central Lower Upper


Contaminated Gloves, 1 min. Worker 0.00000288 4.292E-07 0.00003654

Contaminated Gloves, 1 hour Worker 0.0001728 0.000025752 0.0021924

Spill on Hands, 1 hour Worker 0.000377779 7.23793E-05 0.002782608

Spill on lower legs, 1 hour Worker 0.000930954 0.000178363 0.006857142

General Exposures Worker 0.01575 0.00054 0.096

Table 14. Summary of worker exposure scenarios – Glyphosate 7 lbs acid equivalent /acre


Central Lower Upper


Contaminated Gloves, 1 min. Worker 0.0000087 0.000002146 0.0001764


Spill on Hands, 1 hour Worker 0.001141206 0.000361896 0.013433282



Public Exposure Scenarios - Glyphosate

Table 15. Summary of public exposure scenarios – Glyphosate 6 lbs acid equivalent/acre


Central Lower Upper


Direct Spray of Child, whole body Child 1.43E-02 2.73E-03 1.05E-01

Direct Spray of Woman, feet and lower legs Adult Female 1.43E-03 2.75E-04 1.06E-02

Water consumption (spill) Child 2.73E-01 2.01E-02 2.48E+00

Fish consumption (spill) Adult Male 3.12E-03 3.77E-04 1.88E-02

Fish consumption (spill) Subsistence Populations 1.52E-02 1.84E-03 9.18E-02


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Central Lower Upper


Vegetation Contact, shorts and T-shirt Adult Female 1.26E-03 4.00E-04 3.04E-03

Contaminated Fruit Adult Female 1.41E-02 6.45E-03 2.24E-01

Contaminated Vegetation Adult Female 1.94E-01 1.35E-02 1.62E+00

Swimming, one hour Adult Female 5.23E-09 1.52E-10 1.66E-07

Water consumption Child 9.92E-04 7.15E-05 1.12E-02

Fish consumption Adult Male 1.13E-05 1.34E-06 8.54E-05

Fish consumption Subsistence Populations 5.52E-05 6.52E-06 4.16E-04



Contaminated Vegetation Adult Female 3.11E-02 2.16E-03 2.59E-01

Water consumption Adult Male 6.51E-06 2.11E-06 2.39E-04



Table 16. Summary of public exposure scenarios – Glyphosate 6 lbs acid equivalent /acre


Central Lower Upper




Water consumption (spill) Child 8.25E-01 1.01E-01 1.20E+01





Contaminated Fruit Adult Female 7.06E-02 3.23E-02 1.12E+00







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Central Lower Upper







Worker Exposure Scenarios – Triclopyr Triethylamine Salt

Table 17. Summary of worker exposure scenarios – Triclopyr triethylamine salt 1 lb acid equivalent/acre


Central Lower Upper


Contaminated Gloves, 1 min. Worker 0.0000288 0.0000096 0.0000864


Spill on Hands, 1 hour Worker 0.000506657 0.000138219 0.001994206



Public Exposure Scenarios - Triclopyr Triethylamine Salt

Table 18. Summary of public exposure scenarios – Triclopyr triethylamine salt 1 lb acid equivalent/acre


Central Lower Upper



Direct Spray of Woman, feet and lower legs

Adult Female 1.92E-03 5.25E-04 7.57E-03

Water consumption (spill) Child 1.71E-01 1.67E-02 6.83E-01







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Central Lower Upper












Public Exposure Scenarios - 3,5,6-Trichloro-2-Pyridinol

Table 19. Summary of public exposure scenarios – triethylamine salt 1 lb acid equivalent/acre


Central Lower Upper


Direct Spray of Child, whole body Child No exposure assessment.

Direct Spray of Woman, feet and lower legs Adult Female No exposure assessment.












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Central Lower Upper








Worker Exposure Scenarios – Borate Salt (Disodium Octaborate Tetrahydrate)

Table 20. Summary of worker exposure scenarios – borate salt disodium octaborate tetrahydrate 0.5 lbs/acre


Central Lower Upper


Contaminated Gloves, 1 min. Worker 0.000000468 1.066E-07 0.000000832


Spill on Hands, 1 hour Worker 0.000109819 2.49598E-05 0.000199664

Spill on lower legs, 1 hour Worker 0.000270626 6.1508E-05 0.000492029


Public Exposure Scenarios - Borate Salt (Disodium Octaborate Tetrahydrate)

Table 21. Summary of public exposure scenarios – borate salt disodium octaborate tetrahydrate 0.5 lbs/acre


Central Lower Upper









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Central Lower Upper














Documents

a123.g.akamai.neta123.g.akamai.net/7/123/11558/abc123/forestservic...Human Health Risk Assessment For the Moonlight Restoration Project . Natalie Morgan . May 2. nd, 2017 . In accordance