Was respiratory equipment effective against vermiculite asbestos dust?

There is no data available to evaluate additional factors that influence the effectiveness of respiratory equipment, including proper selection of equipment and fit testing the mask to the individual worker.

There were several points during the process where workers were potentially exposed to dusty conditions, including unloading of the vermiculite from rail cars, use of the forklift and hopper to transfer the materials, bagging of the exfoliated product. Emissions from the vermiculite furnace, dust from processes, and weather conditions affecting air also contributed to worker exposure.

Workers were protected by the use of cotton disposable masks, but adherence to the use of protective facemasks was inconsistent.