1-[[4-(Phenylazo)phenyl]azo]- 2-Naphthalenol (Solvent Red 23)

CAS Registry Number 85-86-9

What is it?

  • 1-[[4-(Phenylazo)phenyl]azo]- 2-naphthalenol, also known as Solvent Red 23, is a red dye.

How is it used?

  • Solvent Red 23 is used primarily in cosmetics and personal care products. It is also used as a colorant in commercial pesticides.
  • The only identified commercial product containing Solvent Red 23 is used as a hard surface disinfectant. No personal care products regulated as drugs, as per the Food and Drug Regulations, have been identified to contain this substance.
  • This substance is not manufactured in Canada but is imported into Canada.

Why did the Government of Canada assess it?

  • Prior to assessment, Solvent Red 23 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.
  • Solvent Red 23 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 into the environment?

  • Solvent Red 23 may be released to the environment during consumer use.
  • A significant proportion of the substance is estimated to be released to wastewaters. Ultimately, Solvent Red 23 is expected to bind to sewage sludge at sewage treatment plants and be sent to landfills. In addition, Solvent Red 23 may be released to soil as a component of an agricultural pesticide.

How are Canadians exposed to it?

  • Canadians may be exposed to Solvent Red 23 when using cosmetics and personal care products that may contain this substance; however, this exposure is expected to be low.

What are the results of the assessment?

  • The Government of Canada has conducted a science-based evaluation of Solvent Red 23 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 Solvent Red 23 has the potential to remain in the environment for a long time, it is not expected to accumulate in organisms.
  • Furthermore, the quantity of Solvent Red 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 Solvent Red 23 is not entering the environment in a quantity or under conditions that constitute a danger to the environment.
  • However, the Government of Canada has also concluded that Solvent Red 23 may be harmful to human health.

What is the Government of Canada doing?

  • Exposure of the general population of Canada to Solvent Red 23 is expected to be low and the Government of Canada is proposing additional action so that exposure remains low.
  • The Government of Canada is proposing the addition of Solvent Red 23 to Health Canada's Cosmetic Ingredient Hotlist, which is an administrative list of substances that are restricted and prohibited in cosmetics.
  • The proposal within the Risk Management Scope to amend the Food and Drugs Regulations under section C.01.040.2(4) which currently permits the use of this colourant in drugs for external use only, remains under consideration.
  • Solvent Red 23 is considered part of the solvent dyes subgroup of the Aromatic Azo and Benzidine-based substances Grouping. Assessment of that grouping was announced in a June 5, 2010 Notice of intent.
  • The final screening assessment report for Solvent Red 23 was published on September 10, 2011 and was followed by a 60-day public comment period (from September 10, 2011 to November 9, 2011).
  • Get more information on Risk Management Action Milestones for Solvent Red 23.

What can Canadians do?

  • The health risks associated with a chemical depend on the hazard (its potential to cause adverse health effects) and the dose (the amount of chemical to which a person is exposed). Exposure to the general population to Solvent Red 23 is expected to be low.
  • As a general precaution, Canadians are reminded when using any product, to carefully follow safety warnings and directions that may appear on a product label.
  • Canadians who handle Solvent Red 23 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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