Assessment of students' exposure to welding fumes in a vocational school welding shop.
Wallace-ME; Lentz-TJ; Fajen-JM; Palassis-J
Appl Occup Environ Hyg 1997 Nov; 12(11):712-715
Welding fume exposure in a vocational school welding shop was examined. Personal breathing zone samples were collected from ten students using polyvinylchloride filter cassettes. Area samples were obtained from the welding and oxy-acetylene torch cutting areas. The samples were analyzed for total welding fume concentration, as well as elemental constituents. Air flow patterns in the room and welding bays were determined using smoke tubes. The air capture rates of the local exhaust hoods were measured using a hot wire anemometer. The concentration of total welding fume in the personal air samples ranged from 3.1 to 10.8mg/m3. Area sample total welding fume concentrations of 2.7 and 3.4mg/m3 were determined. The students were not exposed to welding fume concentrations in excess of the permissible exposure limit for total dust. Likewise, none of the elemental components of the welding fume, such as lead (7439921), chromium (7440473), nickel (7440020), cadmium (7440439), and zinc (7440666), exceeded the OSHA regulatory standards. In six personal air samples, the manganese (7439965) level exceeded the threshold limit value of 200 micrograms per cubic meter (microg/m3). A beryllium (7440417) level close to the NIOSH ceiling limit of 0.5microg/m3 was detected in the personal sample of the one student engaged in metal inert gas welding. Smoke released at the hood faces was captured ineffectively by the ventilation system. Stagnant air was observed at the hoods and near the ducts. Upon inspection, it was found that only one of the three exhaust fans was working properly. The positioning of the local exhaust hoods was also unacceptable. The authors conclude that the ventilation system of the welding shop should be fixed and a preventative maintenance plan implemented in order to protect the students adequately from exposure to welding fumes. The use of personal protective equipment is also encouraged.
NIOSH-Author; Humans; Welders; Metal-fumes; Occupational-exposure; Air-flow; Breathing-zone; Air-samples; Ventilation-systems; Exhaust-hoods; Airborne-particles; Exposure-levels; Dust-exposure; Exposure-limits
7439-92-1; 7440-47-3; 7440-02-0; 7440-43-9; 7440-66-6; 7439-96-5; 7440-41-7
DPSE; EID; DSHEFS
Applied Occupational and Environmental Hygiene