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Issuance of Safe Use Determinations for Diisononyl Phthalate (DINP) in Interface Glasbac® and Glasbac®RE Modular Carpet Tiles

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 diisononyl phthalate (DINP)[2] in Interface GlasBac® and GlasBac®RE modular carpet tiles.  The request was made by Interface, Inc. pursuant to Title 27 of the California Code of Regulations, section 25204(b)(3). 

The only products covered by this request are Interface GlasBac® and GlasBac®RE modular carpet tiles that contain DINP only in the structural backing layer, with concentration limits specified by the requestor as follows:  the concentration of DINP in the backing layer is no more than 9% by weight in GlasBac®RE modular carpet tiles and 16.06% by weight in GlasBac® modular carpet tiles.  As the structural backing layer comprises 56% of the mass of the total tile, these concentrations are equivalent to a DINP concentration in the whole tile of 5.04% by weight in GlasBac®RE modular carpet tiles and 9% by weight in GlasBac® modular carpet tiles.

In accordance with the process set forth in Section 25204(f), OEHHA held a written public comment period on this request from May 19 to June 5, 2017.  No public comments were received.

As provided in Sections 25204(a) and (k), OEHHA is issuing the following SUDs only to Interface, Inc. for DINP in Interface GlasBac® and GlasBac®RE modular carpet tiles with DINP content as specified in the request[3]:

  1. OEHHA is issuing a safe use determination for DINP exposures to professional carpet installers from Interface GlasBac® and GlasBac®RE modular carpet tiles that do not exceed the DINP content levels specified above. 
  2. OEHHA is issuing a safe use determination for DINP exposures to residents of homes and other facilities from Interface GlasBac® and GlasBac®RE modular carpet tiles that do not exceed the DINP content levels specified above. 

The essential elements and results of OEHHA’s assessment are described in the supporting documentation available at: http://oehha.ca.gov/proposition-65/proposition-65-safe-use-determinations-suds.

Based on the screening level exposure analysis described in the supporting documentation, upper-end estimates of DINP exposures from Interface GlasBac® and GlasBac®RE modular carpet tiles with DINP content as specified above[4] were made for professional carpet installers and residents of buildings where these products are installed.  These estimates, 98.9 micrograms per day for professional installers and 93.1 micrograms per day for residents, were compared to the No Significant Risk Level (NSRL) for DINP of 146 micrograms per day.  Thus, the estimated exposure to DINP from these Interface GlasBac® and GlasBac®RE modular carpet tiles is below the NSRL and corresponds to an excess cancer risk of less than one in 100,000 for both professional carpet installers and building residents.  A warning is not required for workers (i.e., professional installers) for these specific products or for residents in buildings where these specific products are installed.   

Supporting documentation for the Safe Use Determination is available on OEHHA’s website at: http://oehha.ca.gov/proposition-65/proposition-65-safe-use-determinations-suds.

Questions regarding this notice should be directed to:

Michelle Ramirez
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

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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] DINP was listed under Proposition 65 as a chemical known to the state to cause cancer effective December 20, 2013.

[3] DINP is present only in the structural backing layer of the tiles. The concentration of DINP in the backing layer is no more than 9% by weight in GlasBac®RE tiles and 16.06% by weight in GlasBac® tiles (equivalent to a DINP concentration in the whole tile of 5.04% by weight in GlasBac®RE tiles and 9% by weight in GlasBac® tiles).

[4]Ibid.