Effective local exhaust ventilation for controlling formaldehyde exposures during embalming.
Appl Occup Environ Hyg 1992 Dec; 7(12):840-845
The use of local exhaust ventilation systems to control the exposure of embalmers to formaldehyde (50000) vapors was studied. A local exhaust ventilation system was developed for an embalming room containing a single embalming table. Two 6 foot slot hoods on each side of the table were connected by ducts to an exhaust system. A minimum flow rate for effective capture of nitrous-oxide vapors was determined to be about 20 cubic meters/minute. The effectiveness of the local exhaust system was examined by collecting area and personal formaldehyde samples during embalming procedures. Five of 32 personal samples demonstrated formaldehyde concentrations greater than 1 part per million (ppm) while 37 of the 94 personal, area, and duct samples were found to be below the limit of detection. Calculation of the upper confidence limits of the mean of the personal and embalming room area samples demonstrated that the system controlled formaldehyde exposures to 0.73ppm and 0.31ppm, respectively. When the local exhaust ventilation system was compared with the dilution ventilation rate required to achieve the same control over formaldehyde emissions, it was found that use of the local ventilation system would result in lower operating costs.
NIOSH-Author; Occupational-exposure; Preservatives; Exposure-levels; Control-systems; Exhaust-ventilation; Ventilation-systems; Air-sampling
Applied Occupational and Environmental Hygiene