There are a number of potential health hazards associated with the processing of plastics. The raw plastics are rarely used on their own and appropriate precautions should be taken regarding the additives used in the various formulations. Additives used include lead soaps in PVC and certain organic and cadmium dyestuffs.
There is a significant risk of dermatitis from liquids and powders usually from “reactive chemicals” such as phenol formaldehyde resins (before crosslinking), urethanes and unsaturated polyester resins used in the production of GRP products. Suitable protective clothing should be worn.
It is possible for fumes to be generated from the thermal degradation of polymers during hot processing. Engineering controls can minimize the problem. Particular care, however, must be taken to avoid inhalation of pyrolysis products under adverse conditions, for example, purging of the extruder barrel. Conditions of good LEV may be necessary. Problems have occurred, for example, where operators have been overcome by hydrochloric acid gas and suffered from “polymer fume fever” following overheating of PVC and polytetrafluorethylene (PTFE), respectively. The accompanying box details some chemical decomposition products of plastics.