Measurement of short-term exposure to airborne soluble platinum in the platinum industry

A number of cases of respiratory sensitization to soluble platinum have arisen in the U.K. over the last few years, despite measured 8 h TWA exposure levels below the current long-term exposure limit in most cases. One possible cause of sensitization may be as a result of high exposures over short periods. Short-term sampling has been hampered by inadequate sampling and analysis techniques. This investigation has used two types of personal inhalable sampler, with ICP-MS analysis, to take 15 min TWA soluble platinum exposure measurements at three sites. The lower detection limit for soluble platinum salts was approximately 0.01 μg m^-3 for 15 min samples, allowing exposures two orders of magnitude below the exposure limit to be measured. It was found that the majority of short-term exposure levels were significantly below 0.006 mg m^-3. No evidence was found for altered work practices during sampling, indicating that either sensitization is occurring at airborne exposure levels below the exposure limit, or there is an alternate route of exposure.