ENVIRONMENTAL COMPANY OF SAO PAULO STATE – CETESB

REGIONAL CENTRE OF STOCKHOLM CONVENTION ON POPs FORLATIN AMERICA AND THE CARIBBEAN REGION

V INTERNATIONAL TRAINING PROGRAM ON ENVIRONMENTAL SOUND MANAGEMENT ON CHEMICALS AND WASTES, ESPECIALLY ON PERSISTENT

ORGANIC POLLUTANTS (POPs) AND MERCURY (Hg)

Chemical HazardsChemist Edson Haddad

2016

Sao Paulo – SP – Brazil

• Chemicals can only be safely handled if their properties, reactions and behavior in different situations are fully known.

• This knowledge allows for the selection of the appropriate PPE –Personal Protective Equipment, as well as the techniques to be employed for containment, control and environmental monitoring.

Safety with Chemicals

Neutralization, absorption, washing/dilution, soil recovery, monitoring, waste destination.

Control Actions

I worked 20 years and had only one accident.

CHEMICAL HAZARDS

WATER COFFEEOXYGEN

NO SUBSTANCE IS COMPLETELY FREEOF TOXIC EFFECTS TO THE BODY

12 POPsPESTICIDES - Aldrin, dieldrin, chlordane, DDT, endrin, heptachlor,

mirex, hexachlorobenzene and toxaphene;

INDUSTRIAL SUBSTANCES - PCBs (polychlorinated biphenyls) andHCB (hexachlorobenzene);

NON-INTENTIONAL SUB PRODUCTS –hexachlorobenzene; polychlorinated dibenzo-p-dioxins andpolychlorinated dibenzofurans (PCDD/PCDF), and PCBs.

aldrin

mirex

DDT

PCB Dioxins and furans

9 POPs• PESTICIDES - chlordecone, alpha hexachlorocyclohexane, beta hexachlorocyclohexane, lindane, pentachlorobenzene;

•INDUSTRIAL SUBSTANCES - hexabromobiphenyl, hexabromodiphenyl ether and heptabromodiphenyl ether, pentachlorobenzene, perfluorooctane sulfonic acid, its salts andperfluorooctane sulfonyl fluoride, tetrabromodiphenyl ether andpentabromodiphenyl ether;

Chlordecone PentachlorobenzeneLindane

Rapid response to critical questionsin a chemical emergency

• What is the chemical?

• What specific dangers does it present?

• How can I control the risks?

• How can I help the victims?• How to put out a fire?

• Which personal protective equipmentshould I use?

CHEMICAL HAZARDSImportant Characteristics

• PHYSICAL STATE;

• COLOR (ALERT);

• ODOR (ALERT).

• Physical properties – boiling temperature, fusiontemperature, solid, liquid or vapor density, vapor pressure, solubility;

• Chemical properties – heat of combustion, flash point, chemical reactivity;

• Toxicological properties – LD50, LC50, IDLH, route of exposure, exposure limits.

CHEMICAL HAZARDSImportant Properties

Important Characteristics• Physical State – POPs are solid but may be in

the form of solution dissolved in solvents such as xylene or kerosene.

Chemical Physical State Color Odor

Aldrin Solid or solution Light brown todark

Mild (L)Odorless (S)

chlordane Solid or solution Colorless tobrown

Aromatic acre, similar to chlorine

DDT Solid or oily liquid Colorless crystals or off-white powder

Odorless

Polychlorinatedbiphenyls

Oily liquid Colorless tolight yellow

Mild aromatic

Mercury Liquid Silver Odorless

Odor Limit: Kerosene = 1 ppm, Xylene = 0.05 ppm

GASSOLID LIQUID

boilingfusion

condensationsolidification

sublimation resublimation

PHYSICAL PHENOMENA ‐ Changes in states of matter

Boiling Temperature (ºC)• This is the temperature at which the vapor pressure of a

liquid equals the atmospheric pressure. At that temperature, the entire liquid changes to the gas state.

• Substances with low boiling temperature have a high vapor pressure. These are known as volatile substances.

• Boiling temperature of water = 100ºC.• Liquids with high teb tend to contaminate by absorption.

Low teb tend to contaminate by inhalation.

All POPs have a boiling temperature above 300 °C or decompose before boiling.

Mercury Teb is 357oC.

Melting Temperature (ºC)

• It is the temperature for which a solid changes to the liquid state.

• The higher the melting temperature, the lower must be the risk of a substance, since the mobility of the material is lower.

• Water melting temperature = 0ºC.• Liquids and solids can present completely different

risks (inert and reactive).

The vast majority of POPs have a melting temperature exceeding 100 °C .

Vapor Pressure• It is the pressure exerted by the vapors above the

liquid level;• It represents the tendency of a liquid or solid to

produce vapors;• Depends on temperature;• The higher the temperature, the higher the vapor

pressure. Expressed in mmHg;• 760 mmHg is the maximum pressure at sea level.

Vapor PressureTemperature

(oC) Water

(mmHg)Ethyl alcohol

(mmHg)Benzene (mmHg)

-10 2.1 5.6 15

0 4.6 12.2 27

10 9.2 23.6 45

20 17.5 43.9 74

50 92.5 222.2 271

75 289.1 666.1 643

100 760.0 1693.3 1360

Vapor Pressure (mmHg)Water Benzene PCB DDT Toxaphene

17.5 at 20 ºC 74.0 at 20 ºC < 1.0.10-4 at 20 ºC 1.9.10-7 at 20 ºC 0.05 at 113 ºC

The vast majority of POPs have a vapor pressure below 1.10-4 mmHg at roomtemperature. They have low volatility.

Kerosene Xylene

2.1 at 21 ºC 10 at 28 ºC

Mercury

0.002 at 25 ºC1.0 at 126.2 ºC

Density/Relative Density of Liquids

• Density is the ratio between the weight of a substance and the volume it occupies. D = m / v For water the density is 1 g/mL or 1,000 kg/m3

• Relative Density is the ratio between the weight of a liquid and the weight of an equivalent volume of water. It indicates how many times the substance is lighter or heavier than water. It is dimensionless.

Water = 1.0

Xylene = 0.84

PCB = 1.3 to 1.8

Water = 1.0

Relative Density of Liquids

d = mass / volume

All POPs have a liquid density higher than water

Chemical Density (g/mL)Aldrin 1.6 (20 ºC)

PCB 1.3 to 1.8 (20 ºC)Chlordane 1.6 (25 ºC)

Endrin 1.6 (20 ºC)Kerosene 0.8 (15 ºC)

Toxaphene 1.6 (20 ºC)Xylene 0.86 (20 ºC)

Mercury 13.55 (20 ºC)

Liquid Density

Density/Relative Density of Gases and Vapors

DensityIt is the ratio between the weight of a gas and the volume it occupies at atmospheric pressure and 0 ºC. It is expressed in g / L. Air density is 1.29 g/L.

Relative DensityThe relative density is in relation to the air, so it has no units.For a substance, it indicates how many times it is lighter or heavier than the same weight of air.

Relative Density of Gases

Gas Relative Density(air = 1)

Hydrogen Chloride 1.30 Phosgene 3.40 Chlorine 2.46 Sulfur dioxide 2.22 Hydrogen 0.07 Propane 1.52

Vapor DensityThe few POPs vapors are, in theory, heavier than air and therefore remain in low areas with risk of intoxication or combustion.

Only hydrogen, methane, acetylene and ethylene have vapor density lower than air.

All gases and vapors, after an appropriate time, mix with the air, regardless of the density or relative density.

Water Solubility• It is the ability of a substance to dissolve in or mix with

water. The solubility increases with temperature.Units: g of product/L of water or per 100 mL of water.

• Important data to predict the behavior of a substance.

Solubility is useful to evaluate:• Toxicity – Water-soluble chemicals can be more easily

removed from the skin.

• Dispersion in water –Determining the impact and helps define removal techniques.

• Gas/vapor knock down– The efficiency of knock downprocedure on a cloud.

• Extinguishing agent – Water cools the chemical and reduces its flash point.

Water solubilityDescription Solubility

(g/100 mL of water at 25oC)

Soluble for all proportions

>> 100

Very soluble > 50

Soluble 10 to 50

Moderately soluble 1 to 50

Slightly soluble 0.1 to 1

Insoluble < 0.1

Chemical Water Solubilitymg/L

Octanol/WaterPartition

CoefficientLog kow

Aldrin 0.08 5.8

Chlordane 0.2 5.1

DDT 0.0028 6.0

Mirex 0.05 6.4

Mercury insoluble 5.0

POPs have low water solubility.They tend to accumulate in the sediment.

Octanol/Water Partition Coefficient - Log kow

The coefficient informs the potential of a chemicalagent to accumulate in animal fat by measuring yourequilibrium distribution between octanol and water.232

It is thus a way of evaluating the miscibility ofa substance across the hydrophilic solvent (water)and lipophilic (oil or fat).

Octanol/Water Partition Coefficient - KowKOW = Coctanol / Cwater

This coefficient numerically represents how much a liquid substance is distributed in a mix half oil and half water to a certain temperature and pressure.

The higher the Kow the greater will be the solubility in oils, and less in water. As the change in solubility of the substances is very large, a logarithmic scale is used to facilitate their interpretation.

Chemical Log KOW InterpretationHexane 3.9 about 8,000 times more soluble in octanol than in waterButanol 0.88 about 7,500 times more soluble in octanol than in waterAcetone - 0.24 about 2 times more soluble in octanol than in water

Flammable Liquids

Example: Kerosene, Xylene, Styrene, Solvents

These are liquids, blends of liquids, or liquids containing suspended or dissolved solids that produce flammable vapors at a temperature of up to 60.5ºC in closed vessel tests, or up to 65.6ºC in open vessel tests, in compliance with the Brazilian standards or other internationally recognized standards.

• FLASH POINT;• FLAMMABLE LIMITS.

FLASH POINT:The lowest temperature at which a flammable or combustible substance releases enough vapor so that the mixture of vapor and air immediately above its surface can propagate a flame started by an ignition source.

Flammable liquids - flash point below 60.5ºC (closed vessel).

25 ºC

Flash point 15 ºCFlash point 30 ºC

25 ºC

SOURCE: FUNDACENTRO

Flammable Liquids

Chemical F.P.(ºC)Gasoline............................... - 38 to - 45Acetone................................ - 20Ethyl Alcohol......................... 13Xylene……............................ 28Kerosene.............................. > 37.8PCB....................................... > 141.2Hexachlorobenzene ........... 242

Flammable Limits

0% LFL UFL 100%

P + O2 CO2 + H2ONo Combustion No Combustion

Lean Mixture Rich Misture

Combustion

Combustion Occurs

LFL – The lowest concentration of a gas or a vapor in air capable ofproducing a flash of fire in presence of an ignition source (arc, flame, heat).UFL – The highest concentration of a gas or a vapor in air capable ofproducing a flash of fire in presence of an ignition source (arc, flame, heat).

Xylene 1,1 7 % in volumeKerosene 0,7 5 % in volume

Practical considerations:• Permanent monitoring.• Elimination of ignition

sources.• Grounding for transference.

Flammable LimitsPermanent Monitoring

Flammable and Toxic Gases or Vapors

Fire involving POPs• Can generate toxic gases/vapors according to

the chemical nature.• Can generate hydrogen chloride (HCl) and

phosgene (COCl2).

Pentachlorobenzene

Characteristics of Gases

• The most dangerous state.• High mobility.• Additional hazard.• Color and odor.• Density.• Confined areas.

Monitoring of Toxic Substances

TOXIC• For acute exposures, the reference is the IDLH (30 minutes of exposure for irreversible effects).

Chemical IDLH (ppm)Hydrogen Chloride 50Ammonia 300Benzene 2000Phosgene 2Carbon Monoxide 1500Toxaphene 200 mg/m3

m – Xylene 900Mercury 10 mg/m3

Effects of hydrogen chloride inhalationConcentration in air

(ppm) Symptoms

1 – 5 Odor perception

5 – 10 Mucous membranes irritation

35 Throat irritation for short exposure

50 – 100 Little tolerable

100 IDLH 1000 Risk of pulmonary edema and

respiratory failure after short exposure

Center of Assistance and Toxicological Information

Chemical is not synonymous with death!!!

We must be prepared for the worst

• EDSON HADDAD• Emergency Response Sector• Phone: 55 11 3133 3795• 24 h-Phone: 11 3133 4000 or 0800 113560• e-mail: ehaddad@sp.gov.br

Thanks for your attention!!!