Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide (MATCB)

CAS Registry Number 106276-78-2

What is it?

• Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide, also known as MATCB, is the product of a chemical reaction that varies in its chemical structure.

How is it used?

• MATCB is used primarily as a dying agent in the textile industry.
• This substance mixture is not manufactured in Canada but small quantities are imported into Canada.

Why did the Government of Canada assess it?

• Prior to assessment, MATCB was identified as a potential concern to the environment based on available information regarding possible persistence, accumulation in organisms and potential to cause harm to organisms.

How is it released to the environment?

• MATCB may be released to the environment during industrial processing.
• Upon its use, most of the substance mixture is expected to end up in solid waste disposal sites with a smaller proportion being released to waste waters.

How are Canadians exposed to it?

• Canadians may be exposed to MATCB during the use of consumer products (textiles) containing this substance.
• However, exposure of the general population of Canada to MATCB is expected to be low.

What are the results of the assessment?

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

What is the Government of Canada doing?

• The Government of Canada is proposing to implement a Significant New Activity (SNAc) provision for MATCB. This would require that any proposed new manufacture, import, or use of this substance mixture be subject to further assessment before this new activity is allowed.
• The final screening assessment was published on March 6, 2010.

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).
• MATCB is not a concern for the environment or human health at current levels of exposure. However, Canadians are reminded when using any product, to carefully follow any safety warnings and directions.
• Canadians who handle MATCB 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.