A laboratory method for generation of replicate filter samples of asbestos fibers in air.

An exposure chamber for generation of 10 replicate filter samples of asbestos fibers is described. The coefficient of variation of replicate samples from laboratory generated amosite aerosol was less than 2.6% in samples with densities of 15 to 250 fibers/mm2. Thus, generation of replicate filter samples of asbestos fibers was possible on a small scale with good precision. Air ionization by an ion source did not alter the variability of replicate samples at relative humidities of 40% or higher. The exposure chamber is of moderate weight and can also be used in the field for collection of replicate samples from working environments.