Diethyl thiourea as a cause of dermatitis in a car factory.

Diethyl thiourea as a cause of dermatitis in a car factory. Fifteen car assembly workers became sensitized to self-skinning neoprene foam weather strips by contact with the bare forearms for the greater part of the working day. A series of patch tests showed 11 out of 11 tested to be sensitive to diethyl thiourea present in the neoprene as an accelerator. The condition cleared on modification of the assembly process. In the last quarter of 1968, the nursing staff in a car assembly factory reported to one of us (W.G.W) that there was a marked increase in the number of men reporting to the works hospital with irritable rashes affecting particularly the hands and forearms and, in a few instances, the face. Having experienced trouble in 1962 and 1963 with dermatitis caused by an anti-oxidant/anti-ozonant (Nonox ZA) present both in rubber gromets and in windscreen washer tubing, we were struck by the similarity between these two groups of cases. In 1962 and 1963 the cause had been found by patch testing and the condition had cleared when the offending substances had been eliminated from the rubbers handled. In this present outbreak all the men complained of irritation on the hands and the flexor aspect of the forearms and some complained of irritation of the face. On examination there were well-defined, slightly raised, erythematous macules scattered on the anterior aspects of both forearms in all cases, and some men complained of irritation of the face associated with erythematous patches which fluctuated throughout the weeks of observation. Others had areas of dermatitis on other parts of the body which came into contact with rubber depending on the working conditions, e.g., one shoulder, the back of the legs, etc. In all, 15 men were affected. The car body shells are supplied by another division of the group where both door and bonnet sealing strips are applied, but no similar skin troubles had been reported at that factory. Some of the men who were affected attached various components to the body shell and, in so doing, their bare forearms to a greater or less extent came into contact with the rubber weather strips around the bonnet opening. Similarly, mechanics who tuned the engine also came into contact with this sealing strip (Figure) and two men working through the door opening came into contact with the rubber sealing strip of the door opening. It therefore …