Phenol, 4-[[4-(phenylazo)phenyl]azo]- (Disperse Yellow 23)

CAS Registry Number 6250-23-3

What is it?

• Phenol, 4-[[4-(phenylazo)phenyl]azo]-, also known as Disperse Yellow 23, is a yellow dye.

How is it used?

• Disperse Yellow 23 is not currently manufactured in Canada or imported into Canada.
• Disperse Yellow 23 has previously been used as a colorant dye in textiles.

Why did the Government of Canada assess it?

• Prior to assessment, Disperse Yellow 23 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.
• In addition, Disperse Yellow 23 was believed to be in commerce in Canada prior to assessment.

How is it released into the environment?

• The Government of Canada has reviewed information that indicates that Disperse Yellow 23 is not currently in commerce in Canada.
• As a result, it is unlikely that Disperse Yellow 23 is entering the environment as a result of commercial manufacture or use in this country.

What are the results of the assessment?

• The Government of Canada has conducted a science-based evaluation of Disperse Yellow 23 called a screening assessment.
• Results of the final screening assessment indicate that although Disperse Yellow 23 may remain in the environment for a long time, it is not expected to accumulate in or directly harm organisms.
• Furthermore, the quantity of Disperse Yellow 23 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 Disperse Yellow 23 is not entering the environment in a quantity or under conditions that constitute a danger to the environment.
• Because Disperse Yellow 23 is not currently in commerce in Canada, it is not considered to be harmful to human health at current levels of exposure.

What is the Government of Canada doing?

• The Government of Canada is proposing to implement a Significant New Activity or SNAc provision for Disperse Yellow 23. This will require that any proposed new manufacture, import or use of this substance be subject to further assessment before this new activity is allowed.
• The final screening assessment report was published on November 28, 2009.

What can Canadians do?

• Since Disperse Yellow 23 is not presently a concern for the environment or human health, Canadians do not currently need to take any specific actions with respect to this chemical.