Copyright 2012, Blake, Cassels & Graydon LLP

Originally published in Blakes Bulletin on Environmental Law, March 2012

In October 2011, we reported on an unprecedented decision by an independent review board to recommend to Canada's Minister of Environment that he reverse his decision to designate a chemical substance as being toxic under the Canadian Environmental Protection Act (CEPA) (to view our October 2011 article, click here). The substance in question is Decamethylcyclopentasiloxane, which is better known as Siloxane D5. Siloxane D5 is an odourless, colourless liquid that is used in consumer and industrial applications. It is mainly used in blending and formulating personal-care products and cosmetics, and is an intermediate in the production of polydimethylsiloxane silicone polymers.

On February 29, 2012, the Minister of the Environment announced his decision to accept the recommendation of the Siloxane D5 Board of Review that found that Siloxane D5 was not toxic to the environment as defined under CEPA. He therefore annulled his predecessor's decision of January 2009 that concluded that Siloxane D5 was toxic and thereby eligible for addition to CEPA's Toxic Substances List. This unprecedented decision on the part of the Minister means that the Canadian departments of Environment and Health, which are jointly responsible for Canada's toxic substances program under CEPA, have had to admit that they made a mistake in determining the toxicity of one substance included in the government's six-year-old Chemicals Management Plan and "Challenge". This program targeted 200 priority chemical substances for detailed toxic assessment and potential regulation.

The rarely convened Board of Review was established at the discretion of the Minister of the Environment in August 2010 after having received formal objections from industry representatives to his predecessor's decision to conclude that Siloxane D5 was toxic and to propose its addition to CEPA's Toxic Substances List. Typically, very little would stand in the way of the next and final step of finalizing a substance's addition to the list and commencing a process of determining what risk management controls and regulations would be applied to the substance and its use in Canada. However, in this case, the Minister relented to industry arguments that the government risk assessors were wrong and did not have a sufficient or accurate scientific basis to conclude that Siloxane D5 was toxic. It was also pointed out that new scientific information had become available.

In the final analysis, the Siloxane D5 Board of Review provided the Minister and all concerned with an independent and refreshing review of the toxic assessment processes and modelling utilized by both Environment Canada and Health Canada. Hopefully, the review and the Minister's decision will lead to an improved and more credible regulatory regime in this area.

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