Health hazard evaluation report: HETA-2000-0308-2981, Ikens Hardwood Floor Services, Madison, Wisconsin.
In May 2000, the National Institute for Occupational Safety and Health received a health hazard evaluation (HHE) request from management at Ikens Hardwood Floor Services, Madison, Wisconsin. The request concerned potential lead and wood dust exposures during wood floor refinishing. The floor service company had previously evaluated 41various floor finishes for lead content; among these, 15% exceeded the federal action level for lead-based paint (0.5% lead by weight). NIOSH investigators conducted a site visit in June 2000 at a single-family home in Madison, Wisconsin, where Ikens Hardwood Floor Services was refinishing hardwood floors. General area and personal breathing-zone (PBZ) air samples were collected for lead and wood dust during floor refinishing, and settled dust samples were measured for lead content. Four in situ (in place) surface measurements were taken to measure the lead content in the varnish on floors. Results from the short-term task-based PBZ air samples ranged from 1.5 to 25 micrograms per cubic meter (ug/m3) and were below the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) for lead of 50 ug/m3. However, worker exposures during buffing approached the OSHA Action Limit for lead of 30 ug/m3, assuming that buffing would be performed over an 8-hour work day. Tasks with the greatest potential to produce lead exposures were buffing and final sanding combined with buffing. All of the wood dust exposures measured during rough sanding, rough edging, final sanding/buffing, and buffing tasks exceeded the NIOSH Recommended Exposure Limit (REL) of 1 milligram per cubic meter (mg/m3) for wood dust, if extrapolated to full shift. All of the settled dust collected on the floors of rooms during refinishing, but prior to final finishing, had lead concentrations exceeding U.S. Housing and Urban Development (HUD) federal clearance guidelines for residential floor areas (0.43 milligrams per square meter [mg/m2]). NIOSH investigators conclude that a health hazard exists during buffing and sanding hardwood floors. Workers are exposed to wood dust above the NIOSH REL, and lead exposures approach the OSHA Action Level for lead. Surface dust samples contained levels of lead which exceed federal clearance standards for residential areas. This suggests a potential health hazard to small children in the home during refinishing, and after if the floors are not cleaned. Recommendations for using engineering and administrative controls and wearing respiratory protection during refinishing activities are included in the Recommendations section of this report.