Module 4: Occupational Asthma - Lecture (Continued)

4. CAUSATIVE AGENTS:

Table 1. Sensitising agents causing occupational asthma as listed under Schedule 3 of the Compensation for Occupational Injuries and Diseases Act (COIDA)
  1. Isocyanates
  2. Metals: platinum, nickel, cobalt, vanadium or chromium salts
  3. Hardening agents, including epoxy resins
  4. Acrylic acids or derived acrylates
  5. Soldering or welding fumes
  6. Substances from animals or insects
  7. Fungi or spores
  8. Proteolytic enzymes
  9. Organic dust *(eg. flour, grain, wood dust)
  10. Vapours or fumes of formaldehyde, anhydrides, amines or diamines
(*) inserted for purposes of clarification
Note: Reactive airways dysfunction syndrome (RADS) typically follows inhalation of a high concentration of an irritant vapour or gas (eg. chlorine, ammonia, acetic acid, sulphur dioxide), often resulting from an accidental emission in the workplace. This should be considered as a type of asthma caused by a "workplace accident" since these substances do not appear on Schedule 3 of COIDA.

Table 2. Examples of jobs/industries in which occupational asthma has been observed, with suspected or proven causative agents
Industry/Job Type Causative Agent/s
Animal handlers: laboratory/farm/butcher Animal protein (muscle, dander, urine, secretion) insects, moulds, mites
Bakers, millers, farmers Flour, grain, soybean, sesame seed, amylase, mites, moulds, weevil
Clothing, textile Wool, silk, reactive dyes, amines, enzymes, vegetable gums
Detergent manufacture Enzymes
Food processors Seafood, sulphites, flour, spices, egg protein, lactalbumin, coffee, tea, garlic, mushroom
Foundries Resins, isocyanates
Furniture, cabinetry, sawmills Wood dust, urea formaldehyde
Hairdressing Persulphates, henna, sericin, vegetable gums
Horticulture, florists, forestry Flowers, grass, seeds, moulds, insects, pesticide
Hospital, medical laboratories, dental Latex, formaldehyde, glutaraldehyde, mercury, acrylates
Metal refining, plating, grinding Platinum salts, chrome, nickel, cobalt, vanadium, mineral oils
Pharmaceutical manufacture, mixing Antibiotics, enzymes
Plastics, rubber, adhesives:
  manufacture/forming/application		 Isocyanates, anhydrides, amines, acrylates, epoxy resins
Printing Vegetable gums
Soldering, electronics Colophony, other fluxes, amines
Spraypainting, coating Isocyanates, hardening agents, amines
Welding Fluxes, metal fumes

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Postgraduate Diploma in Occupational Health (DOH) - Modules 3 – 5: Occupational Medicine & Toxicology by Prof Rodney Ehrlich & Prof Mohamed Jeebhay is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
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