On October 20, 2011, the Siloxane D5 Board of Review ("Board") released a report3 concluding that decamethylcyclopentasiloxane (D5), an odorless, colorless compound used in a variety of dry-cleaning, personal care and cosmetic products, did not pose a danger to the environment or its biodiversity. This report generated interest not only because it disagreed with Environment Canada's risk analysis and conclusions with respect to D5, but because it was the first ever report from a board of this kind.

In 2008, Environment Canada and Health Canada conducted a screening assessment of D5 under the Canadian Environmental Protection Act, 1999 (CEPA) which concluded that D5 was being released into the environment in a quantity or concentration, or under conditions, that may have an immediate or long-term harmful effect on the environment or its biological diversity. The conclusion relied heavily on the finding that D5 exceeded the regulatory thresholds for "persistence"1 and "bioaccumulation,"2.

As a result, D5 was identified as a chemical to be added to Schedule 1, the List of Toxic Substances, under CEPA. If that step were taken, it would have required the government to institute regulatory measures to mitigate or eliminate the risk, potentially leading to, among other options, a complete ban on the use of the chemical.

Under CEPA anyone wishing to challenge a decision to list a compound as toxic may file a Notice of Objection and request that a board of review be convoked to reconsider the issue.

The Silicones Environmental, Health and Safety Council of North America ("SEHSC") filed such a notice respecting D5 on July 14, 2009, and for the first time in the eleven-year history of CEPA the Minister of the Environment agreed, establishing the Siloxane D5 Board of Review.

The Board, made up of three internationally renowned toxicologists, received submissions from Environment Canada, the SEHSC and two intervenors.3 It conducted a de novo risk assessment to determine the nature and extent of the danger posed by D5 to the environment or its biological diversity. After assessing the submissions, all available scientific information respecting D5 (including new information that was not available to Environment Canada in 2008) and evidence from witnesses across the globe over a two-week hearing, the Board concluded that D5 does not pose such a risk. BLG was counsel to the three scientists conducting the review.

The Board concluded that the screening assessment conducted by government officials in 2008 was flawed, that it used overly-conservative modeling and that it inaccurately characterized the compound's fate in the environment. Further, the Board found that Environment Canada failed to take into account the intrinsic properties of D5 in reaching its conclusions with respect to the persistence and bioaccumulation of the compound.

Furthermore, the Board concluded that, because the compound has likely reached a "quasi-steady-state" within the environment, D5 will not likely pose a danger to the environment or its biodiversity in the foreseeable future.

The Board's Report contained a number of recommendations. These included a recommendation that Environment Canada regularly update its regulations establishing bioaccumulation and persistence thresholds to reflect the current state of the science, and to ensure that risk assessments and models used in screening assessments are accurate, up to date, understandable and transparent. The Board also urged industry to work with government agencies "to fill data gaps and provide relevant commentary and analysis."

Clients may wish to consider invoking a board of review in the future. The Board process in this case, adopted with BLG's assistance, was the first of its kind and will likely guide both government and industry in respect of any future screening assessments of potentially toxic chemicals and boards of review that the Minister may choose to convoke.

Footnotes

1 The persistence of a chemical is an estimate of how long it will remain in the environment or an organism.

2 The process by which chemicals accumulate in organisms from the medium surrounding the organisms, including sources such as food.

3 The Canadian Cosmetic, Toiletry and Fragrance Association and the Coalition consisting of the Canadian Environmental Law Association, The International Institute of Concern for Public Health, Chemical Sensitivities Manitoba and the Crooked Creek Conservancy Society of Athabasca were both granted intervenor status.

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