Health Effects

Although safety hazards related to the physical characteristics of a chemical can be objectively defined in terms of testing requirements (e.g., flammability), health hazard definitions are less precise and more subjective. Health hazards may cause measurable changes in the body--such as decreased pulmonary function. These changes are generally indicated by signs such as shortness of breath. Employees exposed to such hazards must be apprised of both the change in body function and the signs and symptoms that may occur to signal that change.

There are two types of health effects: acute and chronic. Acute health effects generally occur rapidly as a result of short-term exposures of a short duration. Examples of acute health effects include irritants, poisons, corrosives and some target organ effects. (1) Chronic health effects generally occur as a result of long-term exposure and are of long duration. Examples of chronic health effects include: carcinogens, reproductive toxins, sensitizers and target organ effects.(1)

Below are some definitions of health hazards:

(taken from 29 CFR 1910.1200 Appendix A)

• It has been evaluated by the International Agency for Research on Cancer (IARC), and found to be a carcinogen or potential carcinogen, or
• It is listed as a carcinogen or potential carcinogen in the Annual Report on Carcinogens published by the National Toxicology Program (NTP) (latest edition); or,
• It is regulated by OSHA under 29 CFR 1910 as a carcinogen.

Corrosive: A chemical that causes visible destruction of, or irreversible alterations in, living tissue by chemical action at the site of contact. For example, a chemical is considered to be corrosive if, when tested on the intact skin of albino rabbits by the method described by the U.S. Department of Transportation in appendix A to 49 CFR part 173, it destroys or changes irreversibly the structure of the tissue at the site of contact following an exposure period of four hours. This term shall not refer to action on inanimate surfaces.

• A chemical that has a median lethal dose (LD50) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each.

• A chemical that has a median lethal dose (LD50) of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each.

• A chemical that has a median lethal concentration (LC50) in air of 200 parts per million by volume or less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.

Irritant: A chemical, which is not corrosive, but which causes a reversible inflammatory effect on living tissue by chemical action at the site of contact. A chemical is a skin irritant if, when tested on the intact skin of albino rabbits by the methods of 16 CFR 1500.41 for four hours exposure or by other appropriate techniques, it results in an empirical score of five or more. A chemical is an eye irritant if so determined under the procedure listed in 16 CFR 1500.42 or other appropriate techniques.

Sensitizer: A chemical that causes a substantial proportion of exposed people or animals to develop an allergic reaction in normal tissue after repeated exposure to the chemical.

• A chemical that has a median lethal dose (LD50) of more than 50 milligrams per kilogram but not more than 500 milligrams per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each.

• A chemical that has a median lethal dose (LD50) of more than 200 milligrams per kilogram but not more than 1,000 milligrams per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each.

• A chemical that has a median lethal concentration (LC50) in air of more than 200 parts per million but not more than 2,000 parts per million by volume of gas or vapor, or more than two milligrams per liter but not more than 20 milligrams per liter of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.

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Target organ effects

The following is a list of target organ effects including examples of signs and symptoms and chemicals which have been found to cause such effects. These examples are presented to illustrate the range and diversity of effects and hazards found in the workplace, and the broad scope employers must consider in this area, but are not intended to be all-inclusive.

Hepatotoxins: Chemicals which produce liver damage

• Signs & Symptoms: Jaundice; liver enlargement
• Chemicals: Carbon tetrachloride; nitrosoamines, alkanolamines, and glycol ethers

Nephrotoxins: Chemicals which produce kidney damage

• Signs & Symptoms: Edema; proteinuria
• Chemicals: Halogenated hydrocarbons; uranium, alkanolamines, and glycol ethers

Neurotoxins: Chemicals which produce their primary toxic effects on the nervous system

• Signs & Symptoms: Narcosis; behavioral changes; decrease in motor functions
• Chemicals: Mercury; carbon disulfide

Agents which act on the blood or hemato-poietic system:
Decrease hemoglobin function: deprive the body tissues of oxygen

• Signs & Symptoms: Cyanosis; loss of consciousness
• ex. Chemicals: Carbon monoxide; cyanides

Agents which damage the lung: Chemicals which irritate or damage pulmonary tissue

• Signs & Symptoms: Cough; tightness in chest; shortness of breath
• Chemicals: Silica; asbestos

Reproductive toxins: Chemicals which affect the reproductive capabilities including chromosomal damage (mutations) and effects on effects on fetuses (teratogenesis)

• Signs & Symptoms: Birth defects; sterility
• Chemicals: Lead; DBCP

Cutaneous hazards: Chemicals which affect the dermal layer of the body

• Signs & Symptoms: Defatting of the skin; rashes; irritation
• Chemicals: Ketones; chlorinated compounds

Eye hazards: Chemicals which affect the eye or visual capacity

• Signs & Symptoms: Conjunctivitis; corneal damage
• Chemicals: Organic solvents; acids

If you have any additional questions, please feel free to contact the Safety, Health & Environmental Group.

PREPARED BY: Kathryn F. Strang
Manager, Safety, Health & Environmental
August 1, 1997
610-832-4304

THIS INFORMATION IS FOR EDUCATIONAL PURPOSES ONLY.

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