Assessment of the performance of respirators in the workplace

The efficiency of a mask currently used in an inorganic pigment manufacturing plant producing suspected carcinogens was assessed and the protection provided by it was found to be insufficient. Three other masks, with better laboratory performances, were tested in field conditions. None of them reduced personal exposures to below the French limit values, and their performance in the field was well below that in laboratory assessments. A similar study in another pigment manufacturing plant gave similar results. Possibly only power-assisted filtering devices will provide satisfactory working conditions.