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 December 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 executive management of global SEHSC member companies 

to respond appropriately to feedback received from the Agency during the December 6th 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 wastewater 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 environmental 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 scientific 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 future.” (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