For Employers’ duties see HERE
Asthma is not well understood, and occupational asthma is frequently defined in terms of exclusion from other definitions. It consists of a constriction of the airways resulting in shortness
of breath, sometimes accompanied by hay fever-like reactions or a cough or both. These symptoms can be mild or severe in degree. An attack of asthma can be very distressing, on occasions requiring hospitalization and can last up to 2 hours. They vary in frequency, but often occur at night. In the case of some people an attack comes on within minutes of exposure, while in others the attacks occur later. There is usually no attack on the occasion of first exposure to the asthma-causing agent. Typically in occupational asthma there is a relief over a holiday or week end period.
The following is a selection of substances causing occupational asthma:
Substance Occupation
2,4-dinitro-O-cresol : Farming and Horticulture
Acrolein : Chemical workers Diazomethane : Chemical workers
Dinitro-phenols : Printing and Dying
Isocyanates : Paint & Chemical Workers
Toluene di-isocyanate : Plastic & Rubber Workers
Salts of Platinum : Platinum refining
Epoxy resins : Chemicals & Construction
Rosin in soldering flux : Soldering
Small animals : Vets & Lab Workers
Grain and flour and
mould and mites of same : Millers & Bakers
Antibiotics : Farmers & Health Workers
Wood dust : Carpenters
Oysters : Oyster Workers
Tea dust : Tea Workers
Tobacco : Tobacco Workers
Colophony : Electronics Workers
Gum acacia : Printers
Papain : Meat processors
Subtilisins : Detergents Workers
Not every worker will contract asthma on exposure but the estimates of proportions of workers who do varies from 5% to 50% depending on the relative substance. Usually, removal from exposure will relieve symptoms but not in all individuals. In addition these may be sensitized to other substances which will also bring on attacks. In the United Kingdom it has been estimated that 40% of workers in the grain business have occupational asthma and in bakers the level is 5 -10%.
The incidence of asthma in workers in the electronics industry is increasing due to metal soldering
There is a kind of adhesive used to put labels on cans and jars, called a “hot pick-up” (HPU), that is potentially a major cause of rosin vapor exposure. The adhesive contains about 80% rosin and is applied hot from open tanks of molten adhesive. The odor of molten rosin is strong and permeates the environment of any factory that does canning.
The amount of HPU used is in excess of 5 million lbs/yr in the US alone which represents a lot of worker exposure to molten rosin vapors. I’ve always wondered how his application has escaped the notice of regulatory agencies.
I’ve personally known of several people who’ve ended up in hospital emergency rooms after occupational exposure to rosin in HPU’s.