January 21, 2014

Mr. Mark Seltzer

Chemical Control Division (7405M)

Office of Pollution Prevention and Toxics

Environmental Protection Agency

East Building

1200 Pennsylvania Avenue NW

Washington, DC 20460–0001

(via e-mail: seltzer.mark@epa.gov)

Re: Enforceable Consent Agreement Development for Two Cyclic Siloxanes (EPA Docket

Number: EPA–HQ–OPPT–2012–0209)

Dear Mr. Seltzer:

The American Cleaning Institute (ACI) is pleased to provide the following comments on the 

draft Enforceable Consent Agreement (ECA) for environmental testing for the cyclic siloxane

octamethylcyclotetrasiloxane (D4) (EPA Docket Number: EPA–HQ–OPPT–2012–0209) dated 

December 19, 2013. ACI is an Interested Party to the development of the ECA. 

We find the draft ECA has been prepared in a very thoughtful and rigorous manner. This was 

further evidenced by the previous public meetings held by EPA in developing the document. We 

believe the implementation of the ECA test plan will yield valuable data to characterize 

environmental exposures to D4. 

The purpose of the testing program proscribed in the ECA is to collect data which will more 

fully describe environmental exposure of aquatic and sediment dwelling organisms to D4. The 

context of the exposure assessment is the risk assessment of D4 as part of EPA’s assessment of 

TSCA Work Plan chemicals which were announced on March 27, 2013. As part of the March 

28, 2013 meeting of the Siloxane Enforceable Consent Agreement Interested Parties and 

Observers, EPA included in the meeting materials a draft of the outline and Chapter 1 of the Risk 

Assessment Plan. This outline of the Risk Assessment Plan included the conceptual model for 

the environmental assessment of D4 including the agency’s thinking on how components of the 

report would be documented including physical chemistry, fate, releases, exposures, hazard 

assessment, risk characterization and uncertainties. In the intervening months (and possibly 

years) while the environmental exposure test data is being collected under the ECA, we believe it 

would be valuable for the agency to publicly release (to the docket) the information that it 

intends to use in order to characterize the physical chemistry, environmental fate and 

environmental hazards and solicit comments. In addition, we believe it would be valuable for 
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January 21, 2014

the agency to further refine their conceptual model and approach, and make that information 

available to the public for comment.

In addition, we note that the agency is currently sponsoring the peer-review panel for the

December 2012 HHCB environmental risk assessment. The agency has assembled a very 

knowledgeable and seasoned panel that through its first two meetings has provided critical

analysis of that assessment and proposed some significant improvements. Likewise, a number of 

comments were provided to the agency by outside parties to improve their analysis and their 

Work Plan risk assessment process. We believe that a more interactive approach in developing 

the assessments, and greater transparency by the agency during the development of the Work 

Plan risk assessments would improve the quality of the product and result in a more efficient 

process. 

We appreciate EPA’s consideration of our comments and look forward to working closely with 

the agency in the future on this matter.

Sincerely,

Paul C. DeLeo, Ph.D.

Senior Director, Environmental Safety