The Canadian government has confirmed the safety of six monomer substances, used to make polymers for a range of consumer and industrial products.
The final screening assessment – published on the 29 September – concludes that the substances do not meet any of the criteria described in paragraph 64 of the Canadian Environmental Protection Act (Cepa).
The six substances are:
- acrylic acid;
- methacrylic acid;
- n-butyl methacrylate;
- 2-ethylhexyl acrylate;
- butyl acrylate; and
- isobornyl methacrylate.
They are used in: adhesives, sealants, paints, coatings, plastics, rubber materials, paper products, cosmetics and construction materials.
The assessment used the "ecological risk classification of organic substances" approach to predicting the environmental risks, which was published in 2016 by Environment and Climate Change Canada.
This led to a "high" classification for the environmental hazard potential of butyl acrylate, owing to "agreement between the reactive mode of action" and "elevated toxic ratio". Both factors suggest that the chemical has "high potency", the assessment says. There was also evidence that the substance would bind to proteins.
However, the assessment did not further investigate the potential effects, or how they might occur in the environment, because of the expected low exposure, and it classified the environmental risk as "moderate".
"On the basis of current use patterns, this substance is unlikely to result in concerns for the environment in Canada," it says.
In 2017, the government published the draft and ran a public consultation, which led to comments from:
- Basic Acrylic Monomer Manufacturers (BAMM);
- the Canadian Consumer Specialty Products Association (CCSPA);
- Kand Environmental Health and Safety Services; and
- the Methacrylate Producers Association (MPA).
A summary of the comments without attribution and the official responses, is available on the Canadian government website.