Exploration of management options

for

Pentachlorobenzene (PeCB)

Paper for the 6th meeting of the UNECE CLRTAP Task Force on Persistent Organic Pollutants,

Vienna, 4-6 June 2007

Colophon ByAnnemiek van der ZandeSenterNovemThe Netherlands

ForVROM, the Ministry of Environment

Date 20 June 2007

Reference

Status

Updated version on the basis of the outcome of the Sixth Meeting of the Task Force on POPs,4-6 June 2007, Vienna, Austria

Table of Contents

Summary............................................................................................................................................ 3

1 Introduction.................................................................................................................................... 5

2 Characteristics of Pentachlorobenzene......................................................................................6

3 Current sources of emission........................................................................................................7 Production and use...................................................................................................................... 7 Emissions from production and use...........................................................................................7 Unintentional emissions..............................................................................................................8

4 Management options...................................................................................................................11 Overview of existing legislation in the UN-ECE region...........................................................11 Substitution, alternatives and emission control techniques..................................................12 Possible management options..................................................................................................13 Costs and benefits of control....................................................................................................13 Possible management options under the UN-ECE POP protocol..........................................14

5 Reference list............................................................................................................................... 15

Annex: information from questionnaire........................................................................................17

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Summary

Pentachlorobenzene, abbreviated to PeCB, is a cyclic aromatic hydrocarbon with 5 chlorine atoms. It belongs to the group of chlorobenzenes. PeCB has been used in the production of the pesticide quintozene (pentachloronitrobenzene) as feedstock or intermediate. In the past PeCB has been used in combination with polychlorinated biphenyls (PCBs) in heat transfer equipment and in electrical equipment. PeCB nowadays enters the environment mainly due to historic use and unintentional releases, such as by-product formation in thermal processes.

Production, use and emissions

Commercial production of PeCB in the UN-ECE region stopped many years ago. For outside the UN-ECE region this is unkown. PeCB formerly was used for producing quintozene, it might still be present as an impurity in quintozene stockpiles. In the EU the use of quintozene was eliminated in 2002. World-wide quintozene is still used, although it is unclear if it was manufactured using PeCB.PeCB was used in PCB containing equipment. In the 80’s production of PCBs stopped and the use of PCBs in equipment declined considerably in the UN-ECE region. Trace amounts of PeCB might be released into the environment when there are spills of dielectric fluids from PCB-containing equipment. When most of the existing PCB equipment is taken out of service, the PeCB amounts released from spills will tend towards zero.

Unintentional releases of PeCB are mainly due to by-product formation during incineration and combustion processes, thermal metallurgic processes and the production of chlorinated chemicals. Waste incineration is potentially the most significant source of PeCB. PeCB may be produced whenever organic compounds are burned in the presence of a chloride source. In low temperature solid waste incineration and combustion processes, like barrel burning, emission of far larger amounts of chlorobenzenes occurs in comparison with high temperature controlled incineration.Unintentional releases of PeCB may come from the use of pentachlorophenol for wood treatment as it contains PeCB as an impurity. Within most of the EU countries the use of pentachlorophenol already has stopped. In North America pentachlorophenol is still used. Reported emissions in Canada represent approximately 6% of the total annual release of PeCB in Canada.

For the year 2000 the emission of PeCB in the UN-ECE region was calculated to be zero, based on data from individual countries and expert estimates. The reported emissions in Canada in the year 2001 were about 40 kg, of which barrel burning of household waste represents the largest source. TRI data of the US show a total amount of 0.7 tonnes PeCB released in 2005 in the US.

Management options

Commercial production and useIn the UN-ECE region commercial production and use has stopped and use of PeCB no longer occurs. Impacts involved with a ban on the commercial production and use are expected to be negligible.

Releases from quintozene useThe use of quintozene has already stopped in most UN-ECE countries. An alternative production process for quintozene is generally available and applied. Therefore current PeCB releases from this source are very low. When commercial use of PeCB is banned, PeCB-emissions related to quintozene will consequently phase out with time.

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Releases from PCB equipmentPCB is one of the substances scheduled for elimination in the POP-protocol. Actions taken to eliminate the use of PCBs will subsequently eliminate any related PeCB emissions. No additional management actions are required.

By-product formation in thermal processesMeasures given in Annex V to control the emissions of PCDD/F will also lead to a reduction of the emissions of PeCB. No additional management actions are required. Emission reduction by addressing residential/domestic combustion sources, like barrel burning, is difficult to control. Providing a residential waste management infrastructure can be an alternative to open burning of garbage in rural areas. No information on costs and impacts is available.

Wood treatmentIn order to reduce PeCB emissions a possible ban of the use of pentachlorophenol for wood treatment may not balance the environmental gains. Management actions are preferably aimed at reducing PeCB impurities in pentachlorophenol. These actions only concern North America.

Costs of eliminating production and useThere are no additional costs for eliminating the production and use of PeCB, since industry has substituted this use already.

Costs of controlling unintentional emissionsPeCB is emitted as unintentional release from the same sources as the POP compounds dioxins and furans. As measures are already implemented to reduce the emissions of PCDD/F no extra costs are expected for industry to reduce emissions of PeCB.

Costs for consumersPrice increases are not expected, however costs may be involved when barrel burning or residential combustion is restricted.

Costs for state budgetsFor the UN-ECE region costs are expected to be negligible. When management actions or strategies are required, such as measures on barrel burning or residential combustion, costs are involved.

Possible management actions under the UN-ECE POP protocol

Option 1: listing of PeCB in Annex I of the POP protocol in order to prevent production and use.

Option 2: listing of PeCB in Annex I and Annex III of the POP protocol.

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1 Introduction

At the 24th session of the Executive Body the Parties to the POP Protocol decided that Pentachlorobenzene (PeCB) is to be considered as a POP as defined under the Protocol. The EB requested the Task Force to continue with the Track B review of the substance and to explore management options for it. The Task Force was invited to complete the reviews preferably in time for presentation to the 40th session of the Working Group on Strategies and Review (WGSR) in September 2007.

Also at the 24th session of the Executive Body the Parties to the POP Protocol requested the WGSR to prepare a proposal, as appropriate, for revising the Protocol in the light of the on-going work on management options for PeCB. This document “Exploration of Management Options for PeCB“ is, therefore, an important building stone for the Task Force to report on management options for PeCB and together with the report of the Task Force for the WGSR to prepare these proposals.

This document is based on the information in the dossier and its addendum that was used to submit PeCB to be included in the POP Protocol, completed with new information received from a questionnaire and with information available in literature and on the Internet.

At its fifth meeting in Tallinn, 2006, the Task Force agreed that a questionnaire was to be sent to countries and stakeholders including industry within the UN-ECE region. This questionnaire was aimed at gaining a better view on management strategies and options in Europe and North America. In February 2007 the questionnaire was sent to the Parties to the Convention on Long-range Transboundary Air Pollution (CLRTAP) and to a group of stakeholders from industry. Questions concerned production, import and stockpiles, use and substitutes, emissions, contaminated sites and emission reduction measures of PeCB. In total 61 questionnaires were sent, resulting in 13 responses regarding PeCB. The information received from the questionnaire is included in this document. A summary of the results of the questionnaire is presented as an annex to this document. In general it can be stated that the questionnaire yielded relatively limited new data. Because the time between the preparation of the dossiers for the Task Force and the questionnaire was relatively short (2 to 4 years) not much new research was done and not many new inventories were made. Furthermore, data on emissions are scarce because the production and use of most of the POPs under consideration have decreased significantly or have completely stopped.

About this documentThis document gives information on the characteristics of PeCB (chapter 2), an overview of the known use and sources of emissions in the UN-ECE region (chapter 3), and presents information on management options (chapter 4). Sources of information that are used to draft this management strategy options document are listed as references in chapter 5.

How to use this documentThis document is a summary of several sources of information. For a complete and correct interpretation of the information provided in this document it is recommended to consult the sources of information referred to in the text.

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2 Characteristics of Pentachlorobenzene

Pentachlorobenzene (PeCB) belongs to the group of chlorobenzenes. PeCB is a chlorobenzene with five chlorine atoms substituting for hydrogen atoms in the benzene ring.

Chemical structure of pentachlorobenzene:

CAS number: 608-93-5Chemical Formula: C6HCl5

Abbreviation: PeCB

Chemical and physical properties

The physical-chemical properties of PeCB are listed in Table 1.

Table 1. Physico-chemical properties of PeCB [1]

Melting point 86 CBoiling point 277 CVapour pressure 2.2 Pa at 25 CLog Kow 4.8 – 5.18Solubility in water 0.56 mg/l at 20 CAppearance Solid, crystalline, whiteMolecular mass 250.32 g/molDensity 1.834 g/ml at 20 C

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3 Current sources of emission

Production and use In the dossier on PeCB [1] the authors conclude that PeCB appears to be no longer produced in the UN-ECE region. The exception to this may be the Czech Republic, where, as reported in the addendum to the dossier [2] it is unclear whether production of PeCB occurs. The chemical is not listed on the HPV-LVP Chemicals Database of the European Chemicals Bureau (ECB). In the dossier and the addendum no data are given on production, recent or past, outside the UN-ECE region.

Historically PeCB may be used as a fungicide and flame retardant. The dossier on PeCB [1] indicates that it is unknown if PeCB still has these uses.

Specifically, PeCB has been used in the production of the pesticide quintozene (pentachloronitrobenzene) as feedstock or intermediate. The information in the dossier and the addendum indicate that quintozene is no longer produced using PeCB in the UN-ECE region. No data are given on the production of quintozene outside the UN-ECE region.

In the past PeCB was one component of a chlorobenzenes mixture used to reduce the viscosity of polychlorinated biphenyls (PCBs) products employed for heat transfer. PeCB has also been used in combination with PCBs in dielectric fluids used for electrical equipment (capacitors, transformers etcetera). Since the 80’s the use of PCBs in equipment declined considerably.

Additional information resulting from the questionnaire [5]In their response to the questionnaire Italy, Cyprus, Denmark, France, the Czech Republic, Canada and the UK report no current production of PeCB in their country. The other respondents have no data available to confirm that PeCB is currently not produced. From other information sources it can be concluded that PeCB is not commercially produced in the Netherlands [11]. Most of the respondents (UK, Belgium, US, Canada, Italy, Denmark, Germany, France and the Netherlands) confirm that there is no current use of PeCB in their country. Switzerland and the Czech Republic have no data available on the use of PeCB. In Italy PeCB was used as a flame retardant until 1980. In the UK PeCB was used for the production of quintozene, which stopped in 1991. In the US PeCB is not used as an end-product. It has been used as an intermediate in the production of quintozene. PeCB is subject to a Toxic Substances Control Act Significant New Use Rule requiring notification prior to manufacture, import or processing of 10,000 pounds (4.54 metric tons) or more of PeCB per year per facility for any use. No such notification has been received by the US Environmental Protection Agency.

Emissions from production and useSince PeCB is probably not produced and used anymore within the UN-ECE region, it is unlikely that PeCB nowadays enters the environment as a result of production and current use.

Use for the production of quintozene Since PeCB was used in the production of quintozene it might still be present as an impurity in the product. Use of quintozene therefore might lead to releases of PeCB. World-wide quintozene is still used, but the EU has banned the use. The dossier indicates that as a result of regulations, the use of quintozene in the EU has stopped since June 2002. Furthermore, quintozene nowadays is made by chlorination of nitrobenzene without using PeCB [1]. It is unlikely that there are any stockpiles of

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quintozene containing appreciable quantities of PeCB, since quintozene-producers (Amvac Chemical and Uniroyal Chemical Corporations) have stated that they no longer use PeCB for their production processes. In their comment to the dossier and addendum on PeCB the World Chlorine Council has put forward the possibility that other minor producers of quintozene still may have PeCB as an impurity [3].

Use in PCB-productsPeCB was one component of a chlorobenzenes mixture used with PCBs in electrical equipment and in equipment for heat transfer. Trace amounts of PeCB are released to the environment when there are spills of dielectric fluids used for PCB transformers that contain these substances. Such spills would be expected to occur from in-use equipment as opposed to equipment in storage. PCBs are taken out of service in many countries of the world so that any related PeCB emissions are expected to be decreasing with time (extracted from the World Chlorine Council submission to the UNEP-questionnaire regarding PeCB considered under the Stockholm POPs Convention, [6]). Some old electrical equipment in North America and Europe may still contain PCBs so that there is a small potential for release of PeCB from these sources.

Unintentional emissionsMunicipal solid waste incineration and barrel burning Waste incineration is identified as a potentially significant source of chlorobenzenes. It is identified that PeCB may be produced whenever organic compounds are burned in the presence of a chloride source. The yield of PeCB formed strongly depends on combustion conditions and the presence of catalytic materials. At low temperatures more PeCB is emitted than at high temperatures. In the addendum of the dossier the authors report that barrel burning of household waste emits far larger amounts of chlorobenzenes than incineration and could be a potentially significant source. The estimated releases from barrel burning represented 52% of the total annual releases of PeCB in Canada in 2001 [2,6].

Hazardous waste incinerationPeCB has been found in releases from hazardous waste incinerators and cement kilns burning waste-derived fuels. Given the temperatures achieved in the hazardous waste incinerator, there is no scientific or practical basis for suggesting that flow-through emissions of PeCB will occur. For the same reasons, any bottom ash residues leaving the incinerator are unlikely to contain PeCB since these compounds would volatilize into the gas stream if present in materials charged to the furnace. The only chlorobenzenes released from hazardous waste incineration would therefore come from their creation in the incineration process [2].

Production of metalsThe formation of chlorobenzenes is likely to occur during various metals production processes, such as the degassing of aluminium, carbochlorination of magnesium oxide, recovery of copper, etcetera [2].

Use of pentachlorophenol for wood treatmentAs cited in the addendum to the dossier, PeCB is contained in pentachlorophenol as an impurity. Pentachlorophenol is used for wood treatment. PeCB releases from wood treatment plants include air emissions, which are generally localized, and releases to water and solid wastes in various forms. Treated wood, such as in-service posts and pilings, also releases PeCB while in use, once land filled or during incineration [2]. Many EU countries have already succeeded in banning the use of pentachlorophenol. As a result of autonomous measures the use will be banned in 2010 throughout the EU. Since the average service life of treated wood is 15 years, PeCB emissions from in use

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treated wood may still occur in the EU, although they are likely to be very low and become negligible with time [13].

Other sourcesPeCB may also be present as an impurity in some fungicides and pesticides, like hexachlorobenzene (HCB. Since the use of HCB has virtually ceased, the release of PeCB through this route is negligible. Other identified sources of PeCB-emissions are the production and use of chlorinated solvents, waste streams from pulp and paper mills, iron and steel mills, petroleum refineries, and activated sludge waste water treatment. There may also be releases of PeCB from landfills.

Emission dataThe addendum to the dossier on PeCB reports that in Canada total releases of PeCB have been estimated to be 41.8 kg/year. Table 2 indicates the sources and releases of PeCB in Canada in 2001.

Table 2: Estimated releases of PeCB in Canada, 2001 [2]Source Release of PeCB

(kg/year)Barrel burning of household waste 21.93 kg/yearPentachlorophenol treated wood 2.34 kg/yearPesticide use 6.2 kg/yearDielectric fluid spill and clear up Less than 5.6 kg/yearMunicipal solid waste incineration 2.36 kg/yearHazardous waste incineration 1.84 kg/yearMagnesium production 1.53 kg/yearSolvent use 0.04 kg/yearTotal 41.8 kg/year

In the TNO-study to the effectiveness of the POP Protocol [12] calculated emission data for PeCB in UN-ECE-Europe are given. For the year 2000 the emission in UN-ECE-Europe was calculated to be zero tonnes/year. This value is based on data from individual countries and expert estimates where detailed data are missing.

The World Chlorine Council submission to the UNEP-questionnaire regarding PeCB considered under the Stockholm POPs Convention [6] reports estimated global releases of PeCB (see table 3). The WCC-submission was extracted from Bailey, B., 2007. Pentachlorobenzene – Sources, environmental fate and risk characterization, Euro Chlor Science Dossier (in press). The data provided are calculated by scaling the Canadian data, using emission factors and logic. Therefore a considerable uncertainty exists about the size of each of these estimated PeCB emissions, potentially an order of magnitude. As presented in table 3 global emissions of PeCB are clearly dominated by combustion sources. Of all sources, combustion of biomass (43,900 kg/year), combustion of solid waste (32,740 kg/year) and combustion of coal (6113 kg/year) represent the three largest sources. Industrial sources are relatively minor. Improvements in industrial practices have probably led to significant reductions in environmental concentrations of PeCB, as remarked by the World Chlorine Council [6].

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Table 3: Estimated annual global emissions of PeCB as provided by the World Chlorine Council [5] and [6]. The data provided by the World Chlorine Council were extracted from Bailey, B., 2007. Pentachlorobenzene – Sources, environmental fate and risk characterization, Euro Chlor Science Dossier (in press).Source Release of PeCB

(kg/year)PCB use losses (use in dielectric fluids) 373Chlorinated solvents <2Pesticide use 342Chemical manufacturing and waste disposal 431Aluminium casting 1100Combustion of solid waste 32,740Combustion of coal 6113 Combustion of biomass 43,900Total annual emission 85,001

Additional information resulting from the questionnaire [5]The US indicate that PeCB may be produced as a by-product or impurity during the production of chlorinated organic compounds. The following data are provided, as extracted from the Toxics Release Inventory (data for all U.S. pentachlorobenzene industries):

for 2004, a total of 2,533 lb. (1.14 tonnes) was reported to the Toxics Release Inventory for on-and off-site disposal or other releases, of which 238 lb. (0.11 tonnes) was released to air and water and of which 2296 lb. (1.03 tonnes) was disposed off to landfills;

for 2005 the total PeCB reported was 1,545 lb. (0.70 tonnes) of which 244 (0,11 tonnes) was released to air, 3 (0,01) to water and 1,297 (0,58 tonnes) was disposed off to landfills.

The Czech Republic reports 19.1 tonnes of PeCB transferred to waste in 2005 in their response to the questionnaire. The World Chlorine Council has provided the data as are presented in table 3 of this management document.Canada has provided the data as presented in table 2 of this management document. For releases of dielectric fluids Canada reports that the current rate of chlorobiphenyl attrition will lead to a discontinuation of the use of PeCB found in equipment containing PCBs. When most of the existing PCB equipment is taken out of service the amounts released from spills fluids will tend towards zero (scheduled for December 31, 2009 for equipment containing 500 mg/kg or more PCB, December 31, 2014 for equipment containing between 50 and 500 mg/kg of PCBs and December 31, 2025 for specified equipment containing 50 mg/kg or more of PCBs). For releases of chlorinated solvents: PeCB has not been detected in the emissions of the only chlorinated solvent manufacturing facility in Canada. However, small amounts of PeCB are found in perchloroethylene and carbon tetrachloride. The two most important sources of releases for perchloroethylene are dry cleaning and solvent degreasing. Two regulations that came into effect in 2003 for the dry cleaning sector and the solvent degreasing sector, will work towards reducing the use of perchloroethylene. As a result PeCB releases will also be reduced. Furthermore PeCB can be found as an impurity in quintozene and other pesticides, several herbicides and fungicides currently in use in Canada.

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4 Management options

Overview of existing legislation in the UN-ECE region

National regulationIn Canada PeCB was added to the List of Toxic Substances of the Canadian Environmental Protection Act in 2005. The ultimate environmental objective of this is virtual elimination of the release to the environment. The Regulations Amending the Prohibition of Certain Toxic Substances Regulations, 2005 (2-Methoxyethanol, Pentachlorobenzene and Tetrachlorobenzenes) prohibit the manufacture, use, sale, offer for sale and import of PeCB, or any mixture or product containing PeCB, except where they are used with chlorobiphenyls or they are contained in a pest control product. Canadian regulations allow the use of PeCB in chlorobiphenyl liquid such as liquid used for servicing equipment containing chlorobiphenyls, which is regulated under the Chlorobiphenyls Regulations and the Storage of PCB Material Regulations. The addendum to the dossier reports more specific regulations and strategies towards the various sources of PeCB-emissions in Canada, like barrel burning, wood treatment, perchloroethylene use, etcetera [2].

PeCB is identified as a level II substance on the Great Lakes Binational Toxics Strategy under the Great Lakes Water Quality Agreement between the U.S. and Canada. The strategy works towards the goal of virtual elimination of certain toxic persistent substances, resulting from human activity, from the Great Lakes Basin.

PeCB is subject to a Toxic Substances Control Act Significant New Use Rule requiring notification prior to manufacture, import or processing of 10,000 pounds (4.54 metric tons) or more of PeCB per year per facility for any use. The U.S. Safe Drinking Water and Clean Water Acts include PeCB. The U.S. Environmental Protection Agency (EPA) has listed PeCB as a hazardous constituent in the US Resource Conservation and Recovery Act (RCRA). Anyone who generates, transports, treats, stores or disposes of waste containing PeCB must notify the US EPA within 90 days. Emissions/releases must be reported as part of the U.S. Toxics Release Inventory (TRI) program.

PeCB is listed as a priority chemical in the Netherlands under the Indicative Environmental Multi-Year Programme. There is an emission limit for PeCB within the NeR, the Dutch Emission Guideline on Air. International regulationInternational focus on PeCB includes a listing as a priority substance of the EU Water Frame-work Directive. Within the list of these priority substances a group of so-called priority hazardous substances is identified which are of particular concern for the freshwater, coastal and marine environment. These substances will be subject to cessation or phasing out of discharges, emissions and losses within an appropriate timetable that shall not exceed 20 years. PeCB is regarded as a priority hazardous substance. PeCB appears on the OSPAR DYNAMEC list in Group V: Substances with PTB properties, but which are heavily regulated or withdrawn from the market.

In the EU quintozene is not included as an active substance in Annex I to Directive 91/414/EEC, which means that Member States shall ensure that authorizations for plant protection products containing quintozene are withdrawn and that no authorizations will be granted or renewed (the use of quintozene will stop after June 2002) [1]. In their response to the questionnaire the UK refer to the Council Directive 90/533/EEC (amending Directive 79/117/EEC) which bans the use of quintozene with more than 10g/kg PeCB since 1991 [5].

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Substitution, alternatives and emission control techniques The dossier on PeCB and the addendum to the dossier do not extensively elaborate on alternatives/substitutes for PeCB. From the strongly decreased use it can be assumed that the substance has been replaced by other chemicals or by application of other techniques, as described below. Other information sources confirm the availability of alternatives.

For the production of quintozene an alternative production process is available. Quintozene nowadays is made by chlorination of nitrobenzene without using PeCB [1].

It has been proven to be a difficult task to find suitable substitutes to PCBs in equipment, particularly for existing equipment with long lifetimes, such as transformers. Nevertheless, by the 80’s chemical companies within the UN-ECE region had stopped production and marketing of PCBs [10]. PCB is one of the substances scheduled for elimination in the POP-protocol. Requirements, as given in Annex II of the protocol, concern the elimination of PCB application in equipment by 2010, the destruction or decontamination of liquid PCBs by 2015 and the decontamination or disposal of PCB-containing equipment in an environmentally sound manner. To reduce and control PCB releases ICCA/WCC/EuroChlor and their member companies consider it appropriate that equipment containing PCBs are labeled and regularly inspected for any leakage. They support the call for safe and environmentally sound destruction of all PCBs [10].

PeCBs can be emitted from the same sources as described for dioxans and furans (PCDD/F) in Annex V of the POP-protocol: waste incineration, thermal metallurgic processes and combustion plants providing energy. Annex V contains several emission control techniques that will also lead to a reduction of PeCB emissions. The removal efficiency for PeCB may not be equal to that for PCDD/F [1]. Emission reduction by addressing residential/domestic combustion sources that are mostly uncontrolled, like barrel burning, is more difficult to realise. Difficulties concern the legislation, implementation and enforcement of relevant emission control measures [13].Controlled incinerators using air pollution control systems designed to reduce mercury emissions through the use of powdered activated carbon should also effectively control chlorobenzene emissions [15].

For wood preservation various chemical alternatives for pentachlorophenol are reported, like zinc naphthenate, copper naphthenate etcetera [13]. Furthermore alternative materials for application in construction are available, like plastics, concrete, sustainable produced hardwood, untreated wood etcetera. The major challenge to wood producers is selecting the right alternative that is the most cost-efficient replacement [13].

Additional information resulting from the questionnaire [5]The UK reports that the emission of PeCB from incineration is strongly reduced when conditions of high temperature (1100 ºC+) and 2 seconds exposure time are met. This technique is generally available.In their response to the questionnaire the World Chlorine Council states that in many cases current control measures and application of the best available techniques (BAT) and best environmental practices (BEP) to address other byproducts are likely to also reduce byproduct emissions of PeCBs from industrial sources and waste incineration. Therefore the World Chlorine Council questions the environmental benefit and cost-effectiveness of additional measures focused on by-product emissions. The Draft guidelines on best available techniques and provisional guidance on best environmental practices developed under the Stockholm POPs convention [14] describe several measures to control emissions of polychlorinated dibenzo-pdioxins (PCDD), polychlorinated

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dibenzofurans (PCDF), polychlorinated biphenyls (PCB) and hexachlorobenzene (HCB). These measures are also likely to reduce the emissions of PeCB and partly overlap with the measures in the European Best Available Techniques Reference Documents.

Possible management options The assumption that PeCB is currently not produced and used in the UN-ECE region has not been refuted by the responses to the questionnaire. Given this fact, restrictions on either consumption or production of PeCB, presented, probalby will result in no socio-economic impacts within the UN-ECE region.

For the production of quintozene other techniques are already available and implemented by quintozene producers. The use of quintozene has already stopped in most UN-ECE countries. World-wide quintozene is still used, although it is unclear if this quintozene was manufactured with PeCB. Nevertheless, it is unlikely that any stockpiles of quintozene containing appreciable quantities of PeCB are present. Therefore PeCB-emissions from current use of quintozene are expected to be very low. A ban on the use of quintozene will ensure complete elimination of PeCB emissions throughout the UN-ECE-region. However, when commercial use of PeCB is banned, PeCB-emissions related to quintozene will consequently phase out with time.

The use in PCB-applications (dielectric fluids, heat transfer equipment) declined considerably in the last decades. All the chemical companies in the UN-ECE region have stopped production and marketing of PCBs. PeCB nowadays is not used anymore for this purpose. Related PeCB emissions are low and will become zero with time. Emissions from PCBs are already controlled in the POP Protocol. Actions taken to eliminate the use of PCBs will subsequently eliminate any related PeCB emissions, so that no additional management actions are required.

Measures to control the emissions of PeCB from incineration, combustion and thermal metallurgic processes are given in Annex V of the POP-protocol. The approaches described in Annex V to control the emissions of PCDD/F will also lead to a reduction of the emissions of PeCB. No additional management actions are required. Emission reduction by addressing residential/domestic combustion sources, like barrel burning, is difficult to control. Providing a residential waste management infrastructure can be an alternative to open burning of garbage in rural areas. However, no information on costs and impacts is available.

PeCB as impurity might be present in wood preserved with pentachlorophenol. Releases of PeCB from wood treatment plants and from in use treated wood within the UN-ECE region are low. Many EU countries have already succeeded in banning the use of pentachlorophenol, in North America pentachlorophenol is still used. In order to reduce PeCB emissions from wood treatment, a possible ban of the use of pentachlorophenol may not balance the environmental gains. Management actions are preferably aimed at reducing PeCB impurities in pentachlorophenol. Because these actions only concern North America, it is not required to include management options in the POP protocol.

Costs and benefits of control

Costs of eliminating production and useIndustry has substituted PeCB and its use already. As a result no additional costs are expected with eliminating production and use of PeCB within the UN-ECE region. Elimination of PeCB production and use in UN-ECE region will not favour production of PeCB in other countries since the regulation will reduce demand as well as production. The dossier and the addendum [1] and [2] contain no indications that PeCB-containing products are imported in the UN-ECE region.

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Assuming no PeCB-containing products are imported, commerce is not affected by a ban of the use of PeCB within the UN-ECE region.

Costs of controlling unintentional emissionsNo specific information is available on costs of controlling unintentional PeCB-emissions. PeCBs are emitted as unintentional release from the same sources as dioxins and furans (PCDD/F). Measures to reduce PCDD/F-emissions also reduce PeCB-emissions. Since these measures are already part of Annex V of the POP-protocol, no additional costs are expected for industry.

Costs for consumersPrice increases are not expected. Substitutes are already in use and control measures do not lead to additional costs. Costs may be involved when barrel burning or residential combustion is restricted.

Costs for state budgetsCosts depend on the management actions taken. For the UN-ECE region costs are expected to be negligible, given the assumptions that PeCB is no longer produced and used within the UN-ECE region, that PeCB-containing products are not imported, that emission levels are very low and that no additional control measures are required. When management actions or strategies are required, such as measures on barrel burning or residential combustion, costs are involved.

Possible management actions under the UN-ECE POP protocolThe objective of the POPs protocol is to control, reduce or eliminate discharges, emissions and losses of persistent organic pollutants.

OptionsIn order to remediate concerns and risks related to production and use of PeCB it would be possible to:- list PeCB in annex I of the POPs protocol in order to eliminate its production and use,- list PeCB in annex II of the POPs protocol in order to eliminate certain uses,- list PeCB in annex III of the POPs protocol in order to reduce total annual unintentional emissions.

Discussion of the optionsPeCB is not intentionally produced in the UN-ECE region and there is no commercial demand for it. PeCB releases arise from the presence as impurity in products and from unintentional by-product formation in thermal processes. No socio-economic impacts are expected to result from a ban on the commercial production and use of PeCB. Hence, there are no restrictions listing PeCB in annex I of the POP protocol in order to eliminate its production and use.

As PeCB is not used in the UN ECE region anymore there is no need to allow for certain uses of PeCB through a listing in Annex II.

It is possible to list PeCB in annex III of the POP protocol in order to reduce its unintentional emissions in thermal processes, which represents the largest source of PeCB-emissions. The measures to control PeCB emissions are comparable with those for controlling PCDD/F-emissions that are already mentioned in Annex V. Listing PeCB in annex III is expected to have no socio-economic impacts as well.

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5 Reference list

1. Van de Plassche EJ, AMGR Schwegler, M. Rasenberg, A. Schouten. 2002. Pentachlorobenzene. Dossier prepared for the third meeting of the UNECE Ad hoc Expert Group on POPs. Royal Haskoning report L0002.A0/R0010/EVDP/TL

2. Belfroid, A., van der Aa, E. and Balk, F. 2005. Addendum to the risk profile of Pentachlorobenzene (update of the dossier). Royal Haskoning report 9R5744.01/R0005/ABE/CKV/Nijm.

3. Belfroid, A., van der Aa, E. and Balk, F. 2006. Response to the comments on the dossier of Pentachlorobenzene (final report). Royal Haskoning report 9R7510.01/R0003/ABE/DDE/Nijm.

4. Track B Review for the UNECE LRTAP Task Force on Persistent Organic Pollutants. 2006.

5. Responses to Questionnaire on management options for reducing production, use and emissions of Persistent Organic Pollutants (POPs) under the 1998 Protocol on POPs, 2007

6. Responses to request for information on Annex E requirements for PeCB proposed under the Stockholm POPs Convention. 2007. http://www.pops.int/documents/meetings/poprc/prepdocs/annexEsubmissions/submissions.htm  

7. TRI Explorer, U.S. Environmental Protection Agency, available through http://www.epa.gov/triexplorer/chemical.htm

8. ECE/EB.AIR/89, Report on the 24th session of the Executive Body held in Geneva from 11-14 December 2006

9. ECE/EB.AIR/WG.5/2006/10, Technical input for reviewing substances under the 1998 Protocol on Persistant Organic Pollutants, Report to the 38th session of the Working Group on Strategies and Review.

10. Eurochlor risk assesment for the marine environment, OSPARCOM region North Sea. June 2006, available through http://www.eurochlor.org/upload/documents/document90.pdf

11. Factsheets on priority substances listed under the Indicative Environmental Multi-Year Programma, National Institute of Public Health and the Environment (RIVM), available through http://www.rivm.nl/rvs/Images/Chloorbenzenen%205_tcm35-36423.pdf

12. Denier van der Gon H.A.C., van het Bolsscher M., Visschedijk A.J.H. and Zandveld P.Y.J. 2005. Study to the effectiveness of the UNECE Persistent Organic Pollutants (POP) Protocol and cost of additional measures, Phase I: Estimation of emisssion reduction resulting from the implementation of the POP Protocol. TNO-report R2006/194.

13. Denier van der Gon, H.A.C., Visschedijk, A.J.H. and van het Bolsscher, M., 2006. Study to the effectiveness of the UNECE Persistent Organic Pollutants (POP) Protocol and cost of additional measures, Phase II: Estimated emission reduction and cost of options for a possible revison of the POP Protocol, TNO-report 2006-A-R0187/B.

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14. UNEP/POPS/COP.3/INF/4 – Draft guidelines on best available techniques and provisional guidance on best environmental practices relevant to Article 5 and Annex C (Advance version), available through http://www.pops.int/documents/meetings/cop_3/meetingdocs/inf4/zINF4%20advance.pdf

15. Risk Management Strategy for Pentachlorobenzene and Tetrachlorobenzene, Chemicals Control Branch, Environmental Protection Service, June 2005, available through http://www.ec.gc.ca/Toxics/docs/substances/certToxics/rms/en/toc.cfm

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Annex: information from questionnaire

PeCB Production Consumption Alternatives Releases Emission control Additional notesBelgium Unclear. PeCB is produced as a by-product. No use No information No information No informationCanada Never produced PeCB is not currently used in its pure

form in Canada, and, currently, there is no domestic commercial demand for it. Formerly, it could be found in dielectric fluids used to top up PCB transformers and in dyestuff carriers. These applications have either been discontinued (dye carriers) or are being phased out (dielectric fluids). The principal current commercial use of PeCB is as a chemical intermediate in the formation of pentachloronitrobenzene (also known as quintozene), a fungicide. PeCB is present as an impurity in this fungicide. Pentachloronitrobenzene is currently used, but not produced, in Canada. PeCB can also be found as an impurity in several herbicides, pesticides and fungicides currently in use in Canada.

No information For releases of dielectric fluids: When most of the existing PCB equipment is taken out of service (proposed end of use deadlines in the new draft PCB Regulations are December 31, 2009 for equipment containing 500 mg/kg or more PCB and December 31, 2014 for equipment containing between 50 and 500 mg/kg of PCBs and December 31, 2025 for specified equipment containing 50 mg/kg or more of PCBs), the amounts released from spills will tend towards zero. For chlorinated solvents: PeCB has not been detected in the emissions of the only chlorinated solvent manufacturing facility in Canada. However, small amounts of PeCB are found in perchloroethylene and carbon tetrachloride. The two most important sources of releases for perchloroethylene are dry cleaning and solvent degreasing. Total releases of PeCB have been estimated to be 41.8 kg/year: of which 21.93 kg was released by barrel burning of householde waste, 2.34 kg by pentachlorophenol treated wood, 6.2 kg by pesticide use, less than 5.6 kg by dielectric fluid spill and clear up, 2.36 kg by municipal waste incineration, 1.84 kg by hazardous waste incineration, 1.53 kg by magnesium production and 0.04 kg by solvent use.

No information The Regulations Amending the Prohibition of Certain Toxic Substances Regulations, 2005 (2-Methoxyethanol, Pentachlorobenzene and Tetrachlorobenzenes) prohibit the manufacture, use, sale, offer for sale and import of PeCB, or any mixture or product containing PeCB, except where they are used with chlorobiphenyls or they are contained in a pest control product. The Regulations allow the use of PeCB in chlorobiphenyl liquid such as liquid used for servicing equipment containing chlorobiphenyls, which is regulated under the Chlorobiphenyls Regulations and the Storage of PCB Material Regulations. The current rate of chlorobiphenyl attrition will lead to a discontinuation of the use of PeCB found in equipment containing chlorobiphenyls. When most of the existing PCB equipment is taken out of service , the amounts released from spills will tend towards zero.

Cyprus Never produced. Industry and data base of the Department of Labour Inspection

PeCB is not imported in Cyprus. No data is available at the moment whether PeCB is contained in any products imported in Cyprus.

No information No information No information

Denmark Never produced Never used No information No information No information Included in EU-Directive 2000/60/EC, Waterframe

Germany PeCB does not occur on the HPV-LPV Chemicals Data Base of the European Chemicals Bureau (ECB).

PeCB was used as a fungicide or flame retardant, no current use anymore: completely banned as a pesticide,

No information No information No information

PeCB Production Consumption Alternatives Releases Emission control Additional notesregistered in FRG until 1987; in ex-GDR until 1986. Import of planting material containing the substance prohibited. An impurity of the pesticide pentachloronitrobenzene (PCNB or Quintozene) is also banned in Germany.

France no production. It is unknown whether it has been produced intentionally in the past.

it is not known whether PeCB has been used in the past in France

? one known pollution around the Rhine, originating from Germany and having contaminated some areas in France. Very little information available on PeCB contamination levels in soils or watercourses.

No infomation Pentachlorobenzene is mentionned as hazardous substance in the list of prority substances in the field of water policy (directive 2000/60/CE)

Italy unclear Federation of Italian industries of chemicals (Federchimica) has stated to not use the substance from 1980. The principal use was as flame retardant.

? ? ?

The Netherlands

Unclear, no data available Never used No information No information PeCB is one of the priority hazardous substances of the EU Water Framework Directive (Dir. 2000/60/EC) and is listed in the draft Directive for priority substances within the WFD which defines water quality standards for European surface waters. It is the intention to phase out Releases of priority hazardous substances by 2020. There is an emission limit for PeCB within the NeR, the Dutch Emission Directive on Air.

Czech Republic

Stopped, year unknown No/unclear. There are no data concerning from the inventory of sources and releases

No information 19,1 tonnes was transferred to waste in 2005

No information

UK no production, stopped in 1991 PeCB was used for the production of quintozene. It stopped in 1991.

No information No information Reduction of PeCB-emissions from incineration can be realised at high temperature (1100C+) & 2 sec exposure time. With 100% removal efficiency. This technique is generally available.

Council Directive 90/533/EEC (amending Directive 79/117/EEC) banned the use of Quintozene with more than 10g/kg PeCB after 1991

PeCB Production Consumption Alternatives Releases Emission control Additional notesUSA Unclear. PeCB is subject to a Toxic

Substances Control Act (TSCA) Significant New Use Rule requiring notification to EPA prior to manufacture, import, or processing of 10,000 pounds (4.54 metric tons) or more of PeCB per year per facility for any use (58 Federal Register 63516, December 1, 1993, 40 CFR 721.1430). No such notification has been received.

unclear. PeCB is not used as an end product. It has been used as an intermediate in the production of the fungicide pentachloronitrobenzene (quintozene). It may be produced as a byproduct or impurity during the production of chlorinated organic compounds.

No information For 2004, a total of 2,533.23 lb. (1.14 metric tons) was reported to the Toxics Release Inventory for on-and off-site disposal or other releases, 238 lb. (0.108 metric tons) of which was released to air or water (TRI, 2004, data for all U.S. pentachlorobenzene industries; additional data is available at www.epa.gov/triexplorer)

No information

Switzerland Unclear, no data available unclear No information No information No information No information

WCC production stopped, year unknown. PeCB is not known to have any commercial uses at present (Beck 1986; Environment Canada 1993). However, in the past, PeCB was one component of a chlorobenzenes mixture used to reduce the viscosity of PCB products employed for heat transfer (Environment Canada 1993; King et al. 2003). PeCB has also been used in a chlorobenzenes mixture with PCBs in electrical equipment (Environment Canada 2005). PCBs are still in use in some old electrical equipment in North America and Europe so that there is a small potential for release of PeCB from this source (AMAP 2000; Environment Canada 2003). It can be presumed that some PCBs are also still in use elsewhere in the world and some fraction of them contain PeCB. PeCB was used in the past as an intermediate in manufacture of pentachloronitrobenzene (quintozene) (van de Plassche et al. 2001). However, quintozene is now made by chlorination of nitrobenzene (Feiler 2001). PeCB may also have been used in the past as a fungicide and flame retardant (van de Plassche et al. 2001).

No use No information See Stockholm POPs Annex E Submissions on Sources http://www.pops.int/documents/meetings/poprc/prepdocs/annexEsubmissions/submissions.htm. Using the factors and logic outlined in WCC Stockholm POPs Annex E submission on PeCB, the estimated global emissions of PeCB around the year 2000 are summarized in Table 3.3, representing a total of about 85,000 kg/y. As described above there is considerable uncertainty about the size of each of these estimated PeCB emissions, potentially an order of magnitude. The global emissions are clearly dominated by combustion sources. Of all sources, combustion of biomass (43,900 kg/y), combustion of solid waste (32,740 kg/y) and combustion of coal (6113 kg/y) represent the three largest sources. Industrial sources are relatively minor and improvements in industrial practices have probably led to significant reductions in environmental concentrations of PeCB.

See WCC Stockholm POPs Annex E Submissions on PeCB Sources and Trends in the Environment http://www.pops.int/documents/meetings/poprc/prepdocs/annexEsubmissions/submissions.htm. In many cases current control measures and application of BAT/BEP to address other byproducts are likely to also reduce byproduct emissions of PeCBs from industrial sources and waste incineration. Therefore, additional measures focused on byproduct emissions are unlikely to provide any detectable environmental benefit and as a result would not be cost-effective. Guidelines for best available techniques and best environmental practices for minimizing uinintentional or byproduct POPs has been developed under the Stockholm POPs Convention.

Furthermore, exisiting measures have already resulted in a dramatic decline in environmental levels of PeCB. Specifically, PeCB has been observed only at extremely low concentrations essentially everywhere in the environment that has been carefully analyzed. PeCB concentrations in herring gull eggs on the shore of Lake Superior, Canada have dropped by over 90% since the 1970s. Concentrations of PeCB have dropped by over 90% since the 1960s in sediments near the industrially impacted Niagara Falls area of the US and Canada. In the absence of a complete emission inventory it is difficult to be confident that management proposals would achieve the desired result.

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