The Toxic Hazards of Industrial and Occupational Chemicals
Basic information on the toxicity of many of the most commonly encountered and toxicologically significant industrial chemicals is provided in Table IV–4. The table is intended to expedite the recognition of potentially hazardous exposure situations and therefore provides information such as vapor pressures, warning properties, physical appearance, occupational exposure standards and guidelines, and hazard classification codes, which may also be useful in the assessment of an exposure situation. Table IV–4 is divided into three sections: health hazards, exposure guidelines, and comments. To use the table correctly, it is important to understand the scope and limitations of the information it provides.
Abbreviations and designations used in this table are defined as follows: | ||
IARC | = | International Agency for Research on Cancer overall classification (See Health hazard information): 1 = known human carcinogen; 2A = probable human carcinogen; 2B = possible human carcinogen; 3 = inadequate data available. |
TLV | = | American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value 8-hour time- weighted average (TLV-TWA) air concentration (See threshold limit value time-weighted average (TLV-TWA)): A1 = ACGIH-confirmed human carcinogen; A2 = ACGIH-suspected human carcinogen; A3 = ACGIH animal carcinogen. |
ppm | = | parts of chemical per million parts of air. |
mg/m3 | = | milligrams of chemical per cubic meter of air. |
mppcf | = | million particles of dust per cubic foot of air. |
(C) | = | ceiling air concentration (TLV-C) that should not be exceeded at any time. |
(STEL) | = | Short-term (15-minute) exposure limit. |
S | = | skin absorption can be significant route of exposure. |
SEN | = | potential for worker sensitization as a result of dermal contact or inhalation exposure. |
NIOSH CA | = | Judged by the National Institute for Occupational Safety and Health to be a known or suspected human carcinogen (See Occupational Safety & Health Administration (OSHA) regulations). |
OSHA CA | = | Regulated by the Occupational Safety & Health Administration as an occupational carcinogen (See Occupational Safety & Health Administration (OSHA) regulations). |
IDLH | = | Immediately Dangerous to Life or Health air concentration (See Immediately dangerous to life or health). |
LEL | = | For this substance, the IDLH value is set at 10% of the Lower Explosive Limit. |
ERPG | = | Emergency Response Planning Guidelines air concentration values for a 1-hour period of exposure (See Emergency Response Planning Guidelines). |
NFPA codes | = | National Fire Protection Association hazard classification codes (See National Fire Protection Association (NFPA)): 0 (no hazard) <—> 4 (severe hazard). H = health hazard F = fire hazard R = reactivity hazard Ox = oxidizing agent W = water-reactive substance |
The chemicals included in Table IV–4 were selected on the basis of the following criteria: (1) toxic potential, (2) prevalence of use, (3) public health concern, and (4) availability of adequate toxicologic, regulatory, and physical and chemical property information. Several governmental and industrial lists of “hazardous chemicals” were used. A number of chemicals were omitted because no toxicologic information could be found, there are no regulatory standards, or they have very limited use. Chemicals that were of specific interest, those with existing exposure recommendations, and those of frequent use (even if of low toxicity) were included.
Health hazard information. The health hazards section of Table IV–4 focuses primarily on the basic hazards associated with possible inhalation of or skin exposure to chemicals in a workplace. It is based almost entirely on the occupational health literature. Much of our understanding of the potential effects of chemicals on human health is derived from occupational exposures, the levels of which are typically many times greater than those of environmental exposures. Moreover, the information in Table IV–4 unavoidably emphasizes acute health effects. Much more is known about the acute effects of chemicals on human health than about their chronic effects. The rapid onset of symptoms after exposure makes the causal association more readily apparent for acute health effects.
The table is not a comprehensive source of the toxicology and medical information needed to manage a severely symptomatic or poisoned patient. Medical management information and advice for specific poisonings are found in Section I (see “Emergency Evaluation and Treatment”, and “Decontamination”) and Section II (see “Caustic and Corrosive Agents”; “Gases, Irritant”; and “Hydrocarbons”).
Hydrocarbons, which are defined broadly as chemicals containing carbon and hydrogen, make up the majority of substances in Table IV–4. Hydrocarbons have a wide range of chemical structures and, not surprisingly, a variety of toxic effects. There are a few common features of hydrocarbon exposure, and the reader is directed to Section II, for information on general diagnosis and treatment. Some common features include the following:
Skin. Dermatitis caused by defatting or removal of oils in the skin is common, especially with prolonged contact. Some agents can cause frank burns.
Arrhythmias. Many hydrocarbons, most notably fluorinated, chlorinated, and aromatic compounds, can sensitize the heart to the arrhythmogenic effects of epinephrine, resulting in premature ventricular contractions (PVCs), ventricular tachycardia, or fibrillation. Even simple aliphatic compounds such as butane occasionally can have this effect.
Because arrhythmias may not occur immediately, cardiac monitoring for 24 hours is recommended for all victims who have had significant hydrocarbon exposure (eg, syncope, coma, and arrhythmias).
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