Consultation document on octamethylcyclotetrasiloxane(D4): annex 1

Annex 1: Questions for discussion

Environment Canada is seeking to fill data gaps for the development of regulations for D4. Environment Canada is asking stakeholders to prepare for the consultation by reviewing the questions in advance and preparing responses. 

Questions in sections A1- 1 to A1- 3 will be focused on at the consultation while sections A1- 4 and Annex 2 list other questions that may come up during the consultation.

Some stakeholders may also have been contacted by Environment Canada before the consultation regarding some of these questions via a voluntary questionnaire (see Annex 2).

A1- 1: Common questions for products and industrial release regulations

  1. Trends in the use of D4
  2. Are there suitable alternatives available for D4?


  1. Are there concerns with the proposed structure of the Products Regulations?
  2. Are the product categories selected appropriate?
  3. Are there limitations to achieving the proposed concentration limits?

A1- 3: Industrial Release Regulations

  1. Do you have any concerns regarding how the release limits have been calculated?
  2. Are the proposed release limits achievable?  Do you think you already meet the release limit? 
  3. What do you think of the requirement of the Substance Management Plan and the proposed threshold for its application?
  4. Do you have any concerns with the proposed sampling and analysis requirements?
  5. In your opinion, what would be the best option for the determination of the effluent flow rate (when determining the quantity release in the effluent)?
  6. Do you have any concerns with other administrative requirement (annual report, record keeping, etc.)?

A1- 4: Other questions for the Product Regulations:

  1. What is the approximate cost of substitutes?
  2. What is the cost of D4?
  3. What is the average cost of formulations (intermediate products used in final products) containing D4?
  4. Do the identified substitutes change the efficacy of the product?
  5. Are there process/manufacturing equipment changes required to use substitute(s)? If so, what is the estimated cost of upgrading the manufacturing plant to handle the substitute?
  6. How long would it take to reformulate a product?
  7. What are the costs associated with reformulation of a product?
  8. Have reformulation efforts already begun for some products?
  9. How long would it take for a company to comply with the proposed product regulation?
  10. Are there studies to show that the use of leave-on products, such as hair grooming, deodorants, and moisturizers, is not a potential release to water?
  11. How does industry understand the definition of cyclomethicone? (i.e. Is it considered to be the same thing as D4? A polymerized mixture using D4 with residuals of pure D4?)

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