Worker exposure to organic vapors at a liquid chemical waste incinerator

The extent of employee exposure to organic vapors at a liquid/fluid chemical waste incinerator facility was assessed by means of a preliminary survey. The study was conducted at a facility owned by the Metropolitan Sewer District of Greater Cincinnati, Cincinnati, OH. The incineration unit employs a rotary kiln and a cyclone furnace (liquid injection) with a common combustion chamber. A wide variety of liquid industrial chemical wastes are accepted in tank truck quantities. Low flow air pumps were used to collect breathing zone and general area samples on standard 150-mg charcoal tubes. The samples were analyzed by a gas chromatograph equipped with a flame ionization detector. Benzene, methyl ethyl ketone (MEK), toluene and xylene, solvents common to many of the wastes accepted, were selected for determination. The data indicate that the routine operation of this liquid industrial waste incinerator facility results in worker exposure considerably less than the action level (50% of the health standard) for all compounds tested, except benzene. Some workers were at risk of overexposure to benzene if the NIOSH-recommended criteria are used, but not when the OSHA and ACGIH criteria are used. The highest exposure routine operations were cleaning pump strainers after receiving wastes and benzene distillations conducted in the laboratory. The non-routine operation of storage tank entry, which occurred once during the study, resulted in the highest potential exposure of any operation.