Hazardous chemical means a chemical for which there is statistically significant evidence (based on at least one study conducted according to established scientific principles), that acute or chronic health effects may occur in exposed employees, or if it is listed in any of the following:
In most cases, the label will indicate if the chemical is hazardous. Look for key words like caution, hazardous, toxic, dangerous, corrosive, irritant, or carcinogen. Old containers of hazardous chemicals (pre 1985) may not contain hazard warnings.
If you are not sure a chemical you are using is hazardous, review the Material Safety Data Sheet (MSDS) or contact your supervisor, instructor, or the Office of Environmental Health and Radiation Safety.
Irritants are materials that cause inflammation of the body surface with which they come in contact. The inflammation results from concentrations far below those needed to cause corrosion. Common irritants include substances such as:
Irritants can also cause changes in the mechanics of respiration and lung function. These include:
Long term exposure to irritants can result in increased mucous secretions and chronic bronchitis.
A primary irritant exerts no systemic toxic action, either because the products formed on the tissue of the respiratory tract are non-toxic or because the irritant action is more severe than any systemic toxic action. Example: hydrogen chloride.
A secondary irritant's effect on mucous membranes is overshadowed by a systemic effect resulting from absorption. These include:
Exposure to a secondary irritant can result in pulmonary edema, hemorrhage and tissue necrosis.
Simple Asphyxiants deprive the tissue of oxygen. Simple asphyxiants are inert gases that displace oxygen. These include:
Chemical asphyxiants render the body incapable of maintaining an adequate oxygen supply. They are active at very low concentrations (few ppm). These include:
Primary anesthetics have a depressant effect upon the central nervous system, particularly the brain. These include:
Hepatotoxic agents cause damage to the liver. These include:
Nephrotoxic agents damage the kidneys. These include:
Neurotoxic agents damage the nervous system. The nervous system is especially sensitive to organometallic compounds and certain sulfide compounds. These include:
Some toxic agents act on the blood or hematopoietic system. The blood cells can be directly affected or the bone marrow can be damaged. These include:
There are toxic agents that produce damage of the pulmonary tissue (lungs) but not by immediate irritant action. Fibrotic changes can be caused by free silica and asbestos. Other dusts can cause a restrictive disease called pneumoconiosis.
The term carcinogen describes any agent that can initiate or speed the development of malignant or potentially malignant tumors, malignant neoplastic proliferation of cells, or cells that possess such material. A listing of carcinogenic materials can be found in appendix C. Carcinogens commonly used in large quantities at the University include formaldehyde, benzene, ethylene amine, ethylene oxide, and chloroform.
Select carcinogen is any substance that meets one of the following criteria:
- After inhalation exposure of 6-7 hours per day, 5 days per week, for a significant portion of a lifetime, to doses of less than 10 mg/m3
- After repeated skin application of 300 mg/kg of body weight per week
- After oral doses of less than 50 mg/kg of body weight per day
Reproductive hazards are chemicals that affect the reproductive capabilities including chromosomal damage (mutagens) and effects on the fetus (teratogens).
A mutagen affects the chromosome chains of exposed cells. The effect is hereditary and becomes part of the genetic pool passed on to future generation.
A teratogen (embryotoxic or fetotoxic agent) is an agent that interferes with normal embryonic development without damage to the mother or lethal effect on the fetus. Effects are not hereditary.
A sensitizer causes a majority of the exposed population to develop an allergic reaction in normal tissue after repeated exposure to the chemical. The reaction may be as mild as a rash (contact dermatitis) or as serious as anaphylactic shock.
A list of reproductive hazards can be found in Appendix D of this document.
Acutely toxic chemicals are substances falling into the following categories:
A list of acutely toxic chemicals can be found in Appendix B of this document.
Extremely toxic chemicals are substances that cause irreversible neurological damage or death with extremely small doses. Substances in this class include many organic mercury compounds such as dimethyl mercury and MPTP (1-methyl-4phenyl-1, 2, 3, 6-tetrahydropyridine) which can cause irreversible Parkinsonian syndrome. Lab work with these materials requires review by EHRS and typically includes chemical resistant gloves and protective clothing.