Painters Prepping Lead-Paint Surfaces: Researchers find that half-mask respirators do not protect enough for hand sanding or conventional power sanding

Residential and commercial painters spend a lot of time and effort preparing exterior building surfaces for repainting. Surface preparation means sanding, scraping, burning, or otherwise removing old paint that is peeling or flaking and no longer intact. When this old paint contains lead, surface preparation work can expose painters to high levels of lead paint dust. Buildings built before 1980, and particularly those built before 1950, are often coated with one or more layers of lead paint.

Twenty-one painting contractors working in San Francisco joined with the California Department of Health Services to study painters' exposures to lead-paint dust during surface preparation work. The study, in 1994-95, covered work on 12 job sites. The amount of lead in the paint ranged from less than 1% to 42%. The researchers collected two kinds of samples: 25 samples measured workers' total lead exposure during a full shift doing surface preparation, and 58 short-term samples measured the levels of lead that workers were exposed to when using a specific surface preparation method.

Six of 25 full-shift samples showed exposures over the OSHA permissible exposure limit (PEL) of 50 micrograms per cubic meter (µg/m3) (range: 0.8 – 550 µg/m3). This confirmed that painters are often exposed over the OSHA limit if they work unprotected. The short-term sample results showed that painters were most highly exposed when doing dry hand-scraping (average: 71 µg/m3; range: 4 – 230 µg/m3), and particularly when doing dry hand-sanding (average: 420 µg/m3; range: 29 – 1200 µg/m3), and conventional power-sanding (average: 580 µg/m3; range: 65 – 3400 µg/m3). In striking contrast, the lead exposures of painters using vacuum-attached power sanders were 80 to 90% lower than lower than those using conventional hand- or power-sanding (average: 33 µg/m3; range: 4 – 60 µg/m3).

The OSHA Lead in Construction standard requires the use of full-face respirators when using a conventional power sander on lead paint. In practice, though, many painters wear half-mask respirators when power sanding, and this does not protect them enough.

The OSHA standard requires that workers use half-mask respirators (with P-100 filters) when doing dry hand-sanding. However, calculations based on the study results show that, in some cases, using a half-mask respirator is not enough protection.

The study results clearly show that painters should use vacuum-attached power sanders when sanding on surfaces that contain – or may contain – lead-based paint. The OSHA Lead in Construction standard requires that the painter wear a half-mask respirator (with P-100 filters) when using a vacuum-attached power sander. The study results show that the workers who did this were protected enough.

For more information, see: Scholz, Peter F., Barbara L. Materna, David Harrington, and Connie Uratsu: Residential and Commercial Painters' Exposure to Lead during Surface Preparation. AIHA Journal 63:22-28 (2002).

PHOTO CAPTION:
A painter removes lead-based paint using a sander with vacuum attached. (Photo courtesy of California Department of Health Services.)