Investigation of the effects of capacity on asbestos vacuum cleaners

Nine industrial vacuum cleaners, designed for collection of asbestos waste, were tested to determine how the performance was affected when the manufacturer's specified capacity was approached, attained, and exceeded. This determination was assessed by measurement of the airborne asbestos fiber concentration in the vacuum cleaner discharge air and the change in vacuum cleaner suction pressure. Airborne fiber concentrations were found to be far below the present OSHA standard; however, the suction pressure of each vacuum cleaner dropped considerably as the capacity was approached and/or exceeded. All of the units tested except one were able to contain 25% more than their specified capacity without any internal problems, filtering system failure, or total loss of suction pressure.