INDUSTRIAL HYGIENE - GASES, VAPORS, AND SOLVENTS UNIVERSITY OF HOUSTON – DOWNTOWN FALL 2013.

INDUSTRIAL HYGIENE -INDUSTRIAL HYGIENE - GASES, VAPORS, AND GASES, VAPORS, AND

SOLVENTSSOLVENTS

UNIVERSITY OF HOUSTON – DOWNTOWN UNIVERSITY OF HOUSTON – DOWNTOWN

FALL 2013FALL 2013

GAS/VAPORGAS/VAPORFor IH purposes, a substance is a GAS if For IH purposes, a substance is a GAS if this is normal physical state at room this is normal physical state at room temperature (25 degrees C) and one-temperature (25 degrees C) and one-atmosphere pressure. atmosphere pressure.

ExamplesExamples: CO, Cl, Oxygen, and Nitrogen.: CO, Cl, Oxygen, and Nitrogen.

If substance is normally a liquid at normal If substance is normally a liquid at normal temperature and pressure, then the gaseous temperature and pressure, then the gaseous component in equilibrium with liquid state is component in equilibrium with liquid state is a VAPOR.a VAPOR.

ExamplesExamples: CCl4, HCOH, and Benzene.: CCl4, HCOH, and Benzene.

MORE TERMSMORE TERMSVapor Pressure – measure of the Vapor Pressure – measure of the

concentration of the chemical in the air at concentration of the chemical in the air at equilibrium. equilibrium.

Solvents are liquids in which a solute can be Solvents are liquids in which a solute can be dissolved.dissolved.

-Volatility-Volatility

-Polarity (“like dissolves like”)-Polarity (“like dissolves like”)

-Solubility-Solubility

ROUTES OF EXPOSUREROUTES OF EXPOSURE

Dermal absorptionDermal absorption Inhalation of vaporsInhalation of vapors Aerosolized mist of the solution can cause Aerosolized mist of the solution can cause

exposure to solutesexposure to solutes

EXPOSURE FACTORSEXPOSURE FACTORS Temperature and VolatilityTemperature and Volatility ConcentrationConcentration Reactivity (air, moisture, acids and bases)Reactivity (air, moisture, acids and bases)

ORGANIC COMPOUNDSORGANIC COMPOUNDS

Organic Solvents (Table 7-A)Organic Solvents (Table 7-A)

-Hydrocarbons contain carbon and hydrogen -Hydrocarbons contain carbon and hydrogen atomsatoms

-Halogenated hydrocarbons – chlorine, -Halogenated hydrocarbons – chlorine, fluoride, iodine and/or brominefluoride, iodine and/or bromine

HAZARDS OF GASES, LIQUIDS, HAZARDS OF GASES, LIQUIDS, SOLVENTS and VAPORSSOLVENTS and VAPORS

Compressed gas – pressure build upCompressed gas – pressure build up Cryogenic Liquids – frostbite, oxygen Cryogenic Liquids – frostbite, oxygen

deficiencydeficiency FlammabilityFlammability ExplosionsExplosions ReactivityReactivity

HAZARDS OF GASES, LIQUIDS, HAZARDS OF GASES, LIQUIDS, SOLVENTS, AND VAPORSSOLVENTS, AND VAPORS

Flash point - is when a liquid is the lowest temp at which it gives off enough vapor to form an ignitable mixture with the air near the surface of the liquid or in a vessel capable of flame propagation away from the source of ignition

Flammable liquid - CC flashpoint below 100 F and vapor pressure not exceeding 40 psi absolute at 100 F (Class I liquid)

Combustible Liquid - CC flashpoint at or greater than 100 F (Class II – III liquids)

HAZARDS OF GASES, LIQUIDS, HAZARDS OF GASES, LIQUIDS, SOLVENTS, AND VAPORSSOLVENTS, AND VAPORS

Lower and Upper Flammable Limit- mixture of vapor with air that, if ignited, just propagate flame. (% by volume of vapor in air)

Flammable Range (Explosive Range) – includes all the concentrations of a vapor in air between the lower explosive limit (LEL) or lower flammable limit (LFL) and the upper explosive limit (UEL) or upper flammable limit (UFL).

HEALTH EFFECTSHEALTH EFFECTS

IRRITANTSIRRITANTSSolubility vs. Activity Considerations.Solubility vs. Activity Considerations.

Upper Respiratory TractUpper Respiratory Tract

Examples:Examples: Ammonia, Acrolein, Formaldehyde, Ammonia, Acrolein, Formaldehyde, Sulfur Oxides.Sulfur Oxides.

Lower Respiratory TractLower Respiratory Tract

Examples:Examples: Nitrogen Dioxide, Phosgene, Ozone. Nitrogen Dioxide, Phosgene, Ozone.

Both Upper and Lower IrritantsBoth Upper and Lower IrritantsExamples:Examples: Chlorine, Ozone. Chlorine, Ozone.

ANESTHETICSANESTHETICS

Central Nervous System (CNS)Central Nervous System (CNS) depressants; cause narcosis.depressants; cause narcosis.

ExamplesExamples: Most Aliphatic Hydrocarbons or : Most Aliphatic Hydrocarbons or Organic Solvents; Alcohols, Esters, Aldehydes, Organic Solvents; Alcohols, Esters, Aldehydes, Ketones.Ketones.

HEMOLYTIC AGENTSHEMOLYTIC AGENTS

Cause damage to the blood or hematopoietic Cause damage to the blood or hematopoietic system.system.

Examples:Examples: Aniline, Arsine, Benzene, Nitrobenzene. Aniline, Arsine, Benzene, Nitrobenzene.

ASPHYXIANTSASPHYXIANTS

Ability to deprive tissue of oxygen.Ability to deprive tissue of oxygen.

Two Types: Two Types:

– SimpleSimple – physiologically inert gases which act – physiologically inert gases which act by accumulating in sufficient quantity to exclude by accumulating in sufficient quantity to exclude adequate oxygen supply. Examples: COadequate oxygen supply. Examples: CO22, ,

methane, ethane, He, H, N.methane, ethane, He, H, N.– ChemicalChemical – act through direct chemical action – act through direct chemical action

to render the body incapable of utilizing oxygen. to render the body incapable of utilizing oxygen.

Examples: CO, HCN, and HExamples: CO, HCN, and H22S.S.

HEPATOTOXIC AGENTSHEPATOTOXIC AGENTS

Adversely affect liver function.Adversely affect liver function.

Examples:Examples: Carbon Tetrachloride, Chloroform, Carbon Tetrachloride, Chloroform, Nitrosamines, Tetrachloroethane.Nitrosamines, Tetrachloroethane.

NEPHROTOXIC AGENTSNEPHROTOXIC AGENTS

Adversely affect kidney function.Adversely affect kidney function.

Examples:Examples: Most Halogenated Most Halogenated Hydrocarbons, Uranium, Mercury, Lead, Hydrocarbons, Uranium, Mercury, Lead, Cadmium.Cadmium.

NEUROTOXIC AGENTSNEUROTOXIC AGENTS

Interfere with proper function or cause Interfere with proper function or cause damage to the nervous system.damage to the nervous system.

Examples:Examples:

CNS - Organometallic Compounds, CNS - Organometallic Compounds, Methyl Mercury, Tetraethyl Methyl Mercury, Tetraethyl Lead.Lead.

Peripheral - Arsenic, TOCP.Peripheral - Arsenic, TOCP.

SENSITIZERSSENSITIZERS

Agents that cause recurrent effects after Agents that cause recurrent effects after the worker becomes sensitized (allergic) the worker becomes sensitized (allergic) to the toxin. First few exposures may to the toxin. First few exposures may cause no reaction, but then reactions cause no reaction, but then reactions can occur from later contact with small can occur from later contact with small quantities for very short periods of time.quantities for very short periods of time.

CARCINOGENSCARCINOGENS

Stimulate or speed the development of Stimulate or speed the development of cancer.cancer.

Examples:Examples: BCME, Vinyl Chloride, BCME, Vinyl Chloride, Benzidine, Chromium.Benzidine, Chromium.

EVALUATION OF HAZARDSEVALUATION OF HAZARDS

Toxicity of the substance Concentration in the breathing zone Manner of use Length of time of the exposure Control in place Employee susceptibilities

CONTROL OF HAZARDSCONTROL OF HAZARDS

Substitution (i.e. benzene for toluene, xylene)

Engineering controls PPE (respirator, gloves, eye wear)