Issuance of Safe Use Determination for Exposures to Crystalline Silica From The Use of Four WOODWISE® Products
The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) is the lead agency for the implementation of the Safe Drinking Water and Toxic Enforcement Act of 1986[1]. OEHHA received a request for a Safe Use Determination (SUD) for exposures to crystalline silica[2] in four WOODWISE® wood filler products. The request was made by Design Hardwood Products, Inc. (DHPI), pursuant to Title 27 of the California Code of Regulations, section 25204(b)(3).
The only products covered by the request are the following Woodwise® wood filler products, designed for use on hardwood floors, with crystalline silica content as specified:
- Full-Trowel Filler: Designed to spread across the surface of a wood floor and fill any cracks, gaps, or voids in the surface. This product contains no more than 0.6% total crystalline silica, and 0.2% respirable crystalline silica by weight.
- Wood Patch: Designed for spot-filling of a wood floor surface, but can be diluted with water and used similarly to the full-trowel filler product. This product contains no more than 0.6% total crystalline silica and 0.2% respirable crystalline silica by weight.
- Pre-Finish Filler: Designed to fill cracks, nail holes, gouges, and broken edges on pre-finished floors, but can be applied to any wood floor. This product contains no more than 2.0% total crystalline silica and 0.2% respirable crystalline silica by weight.
- No Shrink Patch-Quick: Designed to fill large voids in the surface of a wood floor (e.g., knot holes). This product contains no more than 0.6% total crystalline silica and 0.2% respirable crystalline silica by weight.
In accordance with the process set forth in Section 25204(f), OEHHA held a written public comment period on this request from March 8, 2019 to April 9, 2019. No hearing was requested and no public comments were received.
As provided in Sections 25204(a) and (k), OEHHA is issuing this safe use determination for respirable crystalline silica exposures arising from use of the four WOODWISE® wood filler products with crystalline silica content as specified (i.e., no more than 0.6% total crystalline silica by weight for Full-Trowel Filler, Wood Patch, No Shrink Patch-Quick, no more than 2% total crystalline silica by weight for Pre-Finish Filler, and no more than 0.2% respirable crystalline silica by weight for any of the products) for professional hardwood flooring installers, “do-it-yourself” users of the products, and occupants of homes and other buildings in which these wood filler products have been used.
The essential elements and results of OEHHA’s assessment are described in the supporting documentation available at: https://oehha.ca.gov/proposition-65/proposition-65-safe-use-determinations-suds.
Based on OEHHA’s screening level analysis of the information and data provided by DHPI, the upper-end estimate of a lifetime average respirable crystalline silica exposure concentration for occupational users of the WOODWISE® wood filler products that are the subject of the SUD request[3] is 0.2 micrograms per cubic meter (µg/m3). This exposure concentration falls below the low end of the air concentration range of 0.54 to 15 µg/m3 associated with an extra cancer risk of one in 100,000 derived from occupational epidemiological studies. OEHHA has determined that respirable crystalline silica exposures arising from use of the four WOODWISE® wood filler products fall below the level posing a significant cancer risk for professional hardwood flooring installers, “do-it-yourself” users of the products, and occupants of homes and other buildings in which these wood filler products have been used. Thus, exposures to respirable crystalline silica from use of the four WOODWISE® wood filler products within the scope of the request would not require a Proposition 65 warning.
Questions regarding this notice should be directed to:
Tyler Saechao
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-12B
Sacramento, California 95812-4010
P65Public.Comments@oehha.ca.gov
Telephone: (916) 445-6900
- Silica, crystalline (airborne particles of respirable size)
Chemical Reference
Related Notices
Footnotes and References
[1] The Safe Drinking Water and Toxics Enforcement Act of 1986, commonly known as Proposition 65, is codified at Health and Safety Code section 25249.5 et seq.
[2] Crystalline silica (airborne particles of respirable size) was listed under Proposition 65 as a chemical known to the state to cause cancer effective October 1, 1988.
[3]In deriving this upper-end estimate, the identified scenario is use of the WOODWISE® Full-Trowel Filler product in a single-family home, in which respirable crystalline silica is released into indoor air during the application and sanding of the wood filler product.