Phosphoric acid tributyl ester (Tributyl phosphate) (TBP)

CAS Registry Number 126-73-8

What is it?

  • Phosphoric acid tributyl ester, also known as tributyl phosphate or TBP, is an industrial chemical.

How is it used?

  • TBP is used mainly in industrial settings in aviation hydraulic fluids as a flame retardant, as an extraction solvent for rare earth metals from ores, in the manufacture of uranium trioxide, as a defoaming agent, as a plasticizer and in hydraulic fluid and coatings.  It is also found in some paints and brake fluids. 
  • TBP is not manufactured in Canada, but is imported into Canada.

Why did the Government of Canada assess it?

  • Prior to the assessment, TBP was identified as a potential concern to human health based on its classification by international organizations as a substance which was found to cause cancer in laboratory animals, and based on a moderate potential for exposure to Canadians.

How are Canadians exposed to it?

  • TBP may be found in indoor air and drinking water in Canada.
  • Canadians may be exposed to TBP during use of certain consumer products containing TBP such as paints and brake fluid.
  • Exposure of the general population in Canada to TBP is expected to be low.

What are the results of the assessment?

  • The Government of Canada has conducted a science-based evaluation of TBP, called a screening assessment.
  • The Government of Canada has concluded that TBP is not harmful to human health at current levels of exposure.

What is the Government of Canada doing?

  • Based on the conclusion of the final screening assessment, no further action will be taken on TBP.
  • The final screening assessment report was published on August 22, 2009.

What could Canadians do?

  • Because Canadians' exposure to TBP is expected to be low, the Government of Canada is not currently recommending specific actions by Canadians to reduce their exposure.
  • As a general precaution, Canadians are reminded to carefully follow safety warnings and directions when using products containing TBP.

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