Occupational Asthma

Asthma is an illness characterized by intermittent breathing difficulty including chest tightness, wheezing, cough and shortness of breath. It is a frequently serious and sometimes fatal condition. An estimated 11 million workers in a wide range of industries and occupations are potentially exposed to at least one of the more than 200 agents known to be associated with the development of occupational asthma. OSHA has few specific standards that have been designed to protect employees from the risk of this disease and little national attention has been devoted to this issue. OSHA is developing an action plan to reduce worker exposure to this hazard .

The following organic and inorganic agents are associated with the development of occupational asthma:

• high molecular weight organic dusts, and plant and animal proteins such as those associated with grain dust and laboratory animals (for example, guinea pigs and rabbits) and proteins existing in natural rubber latex;
• low molecular weight reactive chemicals (e.g. platinum salts);
• pharmaceuticals that cause sensitizing asthma (e.g. penicillin);
• non-sensitizing respiratory tract irritants (e.g. chlorine gas, sulfur dioxide, fire smoke).

Occupations associated with asthma include health care; animal handling; work with grains; bakeries; work with red cedar; laboratory work; snow crab and egg processing; manufacture of detergents containing biological enzymes; work with paints, plastics, and adhesives; work with metal salts; jewelry making; nickel plating; the tanning industry; and soldering .

In some cases the risks are exceptionally high. Baker's asthma for example has been reported in up to 30% of all bakers. One study estimates that 17% of hospital staff will have allergic reactions to latex gloves. Another study estimates that 2.9% of all nurses and physicians, 5.6% of operating room nurses, and 7.4% of operating physicians will develop a latex allergy .

The prevention and control of occupational asthma requires more than just the establishment of permissible exposure limits (PELs), because some sensitized individuals become symptomatic at extremely low levels. Comprehensive programs designed to prevent sensitization must include engineering controls, personal protective equipment, work practice controls and medical surveillance.

OSHA has set PELs for some of the agents associated with occupational asthma including cobalt, nickel, platinum salts and certain isocyanates. However, the vast majority of materials causing asthma at work, including latex products, are unregulated. NIOSH has recommended exposure limits for a small number of these unregulated agents.

Last Update: April 30, 2000

By: Serdar Z. Elgun