Upload
destiny-lynch
View
219
Download
2
Tags:
Embed Size (px)
Citation preview
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)