Explosives in workplace air

Status:

completed 04/1995

Aims:

Explosives - in vapour and aerosol form - may cause acute (blood picture changes) and long-term health impairment (carcinogenic effect). Exposure is likely to occur during the production of explosives, mixtures of which are for instance used in tunnel construction or in the mining and quarrying industry. Trinitrotoluene (TNT) is especially used for grenades which are filled with molten TNT (approx. 170°C). Armament waste is an additional problem met in particular in older ammunition factories, where residues of armament production and processing (TNT and decomposition products) are found. Here, exposure may occur in connection with redevelopment activities. Parallel analysis of different explosives and samples from different workplaces has so far been impossible. A suitable analytical method was lacking.

Activities/Methods:

The project was aimed to develop a measuring method enabling simultaneous determination of the following explosives: 2,4,6-trinitrotoluene (TNT), 2,4- and 2,6- dinitrotoluene (2,4 DNT; 2,6 DNT), ethylene glycol dinitrate (EGDN), diethylene glycol dinitrate (DEGN) and nitroglycerol (NGL). The method comprises the following steps: sampling of the explosives on an organic adsorption resin and on a teflon filter, elution in an organic solvent, separation by means of HPLC and determination via UV- detection.

Results:

A measuring method was developed which can be used to determine gelatinous explosives in workplace air. The method satisfies all requirements for measuring methods specified in DIN EN 482 "Workplace atmospheres - General requirements for the performance of procedures for the measurement of chemical agents" and thus allows for a workplace assessment in terms of the limit values applying to glyceryl nitrate (0.5 mg/m3) and glycol dinitrate (0.3 mg/m3). The method is based on the collection of explosive vapours on tenax tubes. Elution of tenax is with methanol. After filtration it is possible to inject the eluate directly into the chromatographer. The method was validated in measurement series carried out in co-operation with the German Berufsgenossenschaft for the chemical industry in explosive warehouses. It turned out to be a universal method which can be transferred to other explosives, too. Whenever semivolatile explosives are sampled (e.g. TNT or tetryl), a teflon filter must be used prior to the tenax tube. Sampling of aerosols shall be in the inhalable fraction. The method is used as a standard method to determine explosives in workplace air within the measuring system for hazardous substances run by the German Berufsgenossenschaften (BGMG).

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