HHE report no. HETA-93-0951-2382, Hodges and King, DDS, Atlanta, Georgia.
NIOSH 1994 Jan; :1-26
In response to a request from the dental office of Hodges and King, DDS (SIC-8021), Atlanta, Georgia an investigation was begun into airborne concentrations of nitrous-oxide (10024972) (N2O) during administration to patients. Employees had experienced fatigue, headache, and eye irritation and felt this could be connected to their work exposure to N2O. During the first survey, personal exposure to N2O averaged over the duration of N2O administration, ranged from 205 to 456 parts per million (ppm) for dentists, from 144 to 465ppm for dental assistants, and 1,950ppm for a dental hygienist. The NIOSH Recommended Exposure Limit (REL) for N2O was 25ppm averaged over the duration of anesthetic administration. General dental office levels ranged from 19 to 277pm, and levels in the lobby of the building ranged from 32 to 65ppm. The system was then tested, and all leaks repaired. Scavengers were installed to control N2O at the point of use. A second survey revealed N2O levels of 60 to 347ppm for dentists, 80ppm for a dental assistant, and 93ppm for a dental hygienist. General dental office levels ranged from 22 to 51ppm and lobby levels ranged from 14 to 27ppm. The authors conclude that N2O levels exceeded the REL, even after measures were taken to reduce exposures. Due to the common air return system, exfiltration to other areas on the same floor occurred. The authors recommend improving the ventilation system, and limiting the use of N2O.
NIOSH-Author; NIOSH-Health-Hazard-Evaluation; NIOSH-Technical-Assistance-Report; HETA-93-0951-2382; Hazard-Confirmed; Region-4; Dentistry; Occupational-exposure; Anesthetics; Nitrogen-oxides; Indoor-air-pollution; Ventilation-systems; Indoor-environmental-quality
Hazard Evaluation and Technical Assistance; Field Studies
NTIS Accession No.
Hazard Evaluations and Technical Assistance Branch, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, Report No. HETA-93-0951-2382, 26 pages, 21 references