Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, reaction products with ammonia, octamethylcyclotetrasiloxane and silica (OMSSA)

CAS Registry Number 68937-51-9

What is it?

  • Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, reaction products with ammonia, octamethylcyclotetrasiloxane and silica, also known as OMSSA, is an industrial chemical.

How is it used?

  • OMSSA is used in industrial settings as a component in the production of silicone sealant and silicone rubber.
  • This substance is not manufactured in Canada but is imported into Canada.

Why is the Government of Canada assessing it?

  • Prior to assessment, OMSSA was identified as a potential concern to the environment based on information regarding possible persistence, accumulation in organisms and potential to cause harm to organisms.
  • OMSSA was not considered to be a high priority for assessment of potential risks to human health; however, potential health effects were also evaluated in this screening assessment.

How is it released to the environment?

  • Potential releases of this substance would be to water and air from industrial releases.

How are Canadians exposed to it?

  • The general population is not likely to be exposed to OMSSA since it is used primarily in industrial settings.

What are the results of the assessment?

  • The Government of Canada has conducted a science-based evaluation of OMSSA called a screening assessment.
  • Screening assessments address potential for harm to the general population (not including workplace exposures) and the environment.
  • Results of the final screening assessment indicate that although OMSSA has the potential to remain in the environment for a long time, it is not expected to accumulate in organisms.
  • Furthermore, the quantity of OMSSA that may be released to the environment is below the level expected to cause harm to organisms.
  • The Government of Canada has therefore concluded that OMSSA is not entering the environment in a quantity or under conditions that constitute a danger to the environment.
  • The Government of Canada has also concluded that OMSSA is not considered to be harmful to the health of the general population at current levels of exposure.

What is the Government of Canada doing?

  • The Government of Canada proposed that no further action be taken on OMSSA.
  • The final screening assessment report was published on June 29, 2013.

What can Canadians do?

  • The health risks associated with a chemical depend on the hazard (its potential to cause health effects) and the dose (the amount of chemical to which you are exposed). OMSSA is not a concern for the environment or human health at current levels of exposure.
  • As a general precaution, Canadians are reminded when using any product to carefully follow any safety warnings and directions.
  • Canadians who handle OMSSA in the workplace should consult with their occupational health and safety representative about safe handling practices, applicable laws and requirements under the  Workplace Hazardous Materials Information System (WHMIS).

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