Contact Dermatitis within the Explosives Industry – a Case Report

Introduction. Explosives are widely used, within the armed forces as well as civilian society, but the health effects associated with the explosive manufacturing industry are not well described. Case report. We present the case of a 48-year-old explosive manufacturing factory operator who developed contact dermatitis to trinitrotoluene as the presumed causative agent and paronychia from prolonged wet work. Discussion. The main health effects of exposure to organic nitrates (including those used in explosives) are dermatitis, methaemoglobinaemia, vasodilation and carcinogenesis. Conclusion. It is essential for health care workers to take a detailed occupational history in order to determine the possible contribution of work to a patient’s health. Fig. 1. Contact dermatitis on the hand and arm. A patch test was performed using the standard battery of 43 international allergens. These were applied under occlusion in Finn chambers for 48 hours. The test was read 24 hours after removal of the chambers. A positive reaction was seen to formaldehyde. Despite a work history that identified some of the chemical exposures and significant water exposure, the patch test was not helpful. Before recommendations could be made regarding further patch testing using his own products, a work visit was undertaken to evaluate exposures and risk. The manufacturing process to which he ascribes his rash involves the mixing of TNT with other chemicals such as cyclotrimethylenetrinitramine (RDX/cyclonite), hexanitrostilbene (HNS) and beeswax in a steam-heated melting kettle to form a paste. This kettle has point extraction in order to extract the dust and vapours generated by the heating of the TNT and other additives. TNT, when it enters the process, is in flocculate form and is poured into the kettle from sacks, so the generation of dust is possible despite extraction. The molten mixture is then solidified in moulded trays overnight forming solid slabs resembling large chocolate bars. PVC and cotton gloves are prescribed as personal protective equipment in this area. The solidified explosives are then transferred by tractor to a separate facility for further processing. Rubber mallets are used to separate the slabs into the individual moulded pieces. This is done under an extraction hood to minimise dust exposure generated in the pounding process. After passing through a sieve they are manually weighed into specially manufactured bags and packaged in accordance with strict regulations. The packaging is taped with paper taping and the boxes stamped using an inkpad. The workers are therefore also potentially exposed to glue and dyes. A third process in the manufacture of explosives in which this worker participated, involved the refinement of the explosive cyclonite. Friction and the generation of sparks is a constant concern in the manufacturing of explosives. For this reason the powdered cyclonite is first manually poured into a running stream of tap water directed from a hose held by the worker to form a slurry which is then piped into reactors containing cyclohexanone. The heated mixture is distilled and allowed to cool to produce cyclonite crystals of specific size. Our patient holds the hosepipe with his right hand, which means that his hand is wet for approximately 4-5 hours while this production step is taking place. Personal protective wear is used but does not help as water constantly contaminates the inner surface of the glove and soon saturates the cotton glove appropriately used inside to reduce maceration of occlusion.