Phone: 703.788.6570

Fax: 703.788.6545

www.sehsc.com
2201 Cooperative Way

Suite 600

Herndon, VA 20171

Ward Penberthy Deputy Director

Chemical Control Division

OPPT/ U.S. EPA

December 18, 2012

Dear Ward:

On behalf of the Silicones Environmental, Health, and Safety Council of North America (SEHSC), I would like to thank you and your colleagues at the US Environmental Protection Agency (EPA), for meeting with representatives of SEHSC on Decem ber 6, 2012, to discuss an environmental monitoring enforceable consent agreement (ECA) proposal for D4 and D5.

SEHSC would like to request that the Agency extend the negotiation period for these ECA negotiations

in order to allow sufficient time for senior exec utive management of global SEHSC member companies to respond appropriately to feedback received from the Agency during the December 6 th meeting. We are committed to generating environmental monitoring data to support a risk assessment for D4, and remain hopeful that collective agreement can be achieved on a program that satisfies the Agency’s goal for developing a risk assessment for D4, is consistent with sound science, and that comports with SEHSC’s commitment to environmental stewardship.

While we believe the existing SEHSC proposal would provide the data necessary to support a risk assessment for D4, SEHSC members would like to continue discussions with the Agency to allow additional time to address the Agency’s concerns. Extending the ECA negotiations will facilitate discussion of potential modifications to the POTW component of the SEHSC monitoring proposal to incorporate additional POTW sites that receive discharges from industrial facilities.

Monitoring SEHSC member facilities that have direct discharges to surface waters in combination with a robust assortment of municipal wastew ater treatment plants (POTWs) will provide an appropriate dataset for conducting an ecological risk assessment for D4. However, collecting data from indirect dischargers will not advance the Agency’s planned risk assessment, because there is no discharge to the environment—or genuine environment al risk—associated with these sites. In addition, monitoring indirect discharge sites will compromise proprietary facility production details and jeopardize innovation.SEHSC further believes that there is no longer any reason to include D5 monitoring in this ECA. The international consensus, based on strong scientif ic evidence, is that there are no significant

risks associated with D5. As Environment Canada stated at the conclusion of an exhaustive Board of Review evaluation: “Siloxane D5 does not pose a danger to the environment or its biological diversity” and “based on the information presented, Siloxane D5 will not pose a danger to the environment or its biological diversity in the fu ture.” (October 2011). There is therefore no need to collect D5 monitoring data under this ECA at this time. Removing D5 from the current negotiations will create additional flexibility for industry with respect to D4 monitoring.

The data generated to date continues to demonstrate that monitoring industrial facilities with direct discharges to surface waters and discharges from POTWs will provide the greatest opportunity to inform the Agency on the release of D4 into the aquatic environment. Consequently, those releases are the appropriate focus for a monitoring program intended to generate data that will support an assessment of the risks associated with D4. SEHSC members are committed to assessing the potential risks associated with D4, and will seek to incorporate the monitoring of additional POTWs with industrial contributions—as envisioned in the Agency’s proposal—into our ongoing international monitoring program, regardless of the outcome of these ECA negotiations. SEHSC members respectfully request further opportunity to discuss a monitoring program that takes into consideration the various viewpoints expressed throughout the ECA process.

Sincerely,

Karluss Thomas Executive Director, SEHSC