CAS Registry Number 123-31-9

The Final Screening Assessment for Hydroquinone was published on July 5, 2008 as part of Batch 1 of the Challenge initiative of the Chemicals Management Plan (CMP). The assessment is summarized on this page.

What is it

  • Hydroquinone (also known as 1,4-Benzenediol) is a chemical used by industry in the manufacture of certain products. It also occurs naturally in some food.
  • This substance is not the same as benzene, which has already been determined to be "toxic" and is regulated under the Canadian Environmental Protection Act, 1999 (CEPA 1999).

How is it used

  • Hydroquinone is used in the production of other chemicals. It is also used in a variety of industrial and consumer adhesives, including as an additive to heat shrink tubing, restorative paste, bonding tape and as a reducing agent in photographic developing solutions.
  • Hydroquinone is used in certain cosmetic products, such as manicure preparations and hair dyes.
  • Hydroquinone is also used in some health products, such as skin lightening preparations.
  • While hydroquinone occurs naturally in some foods, there is no evidence to show that the natural presence of hydroquinone in food poses a health risk to Canadians or that Canadians should avoid foods containing hydroquinone.
  • Based on the most recent data, hydroquinone is manufactured in Canada and imported into Canada.

Why did the Government of Canada assess it

  • Hydroquinone has been shown to cause cancer in some studies with laboratory animals. Although exposures to Canadians are low, the Government of Canada's objective is to minimize exposures to this substance.

What is the Government of Canada doing

  • The Government of Canada has declared hydroquinone "toxic" as defined under CEPA 1999.
  • The Government of Canada will propose additional measures to control any risks posed by hydroquinone including:
    • Proposing to regulate hydroquinone-containing health products as a prescription drug, rather than allowing products containing it to be sold over the counter (such as skin lightening products).
    • Proposing to include hydroquinone as a prohibited or restricted ingredient on Health Canada's Cosmetic Ingredient Hotlist. The Hotlist is used to communicate that certain substances may not be compliant with requirements of the Food and Drug Act or the Cosmetic Regulations. Under Canadian legislation, cosmetics that contain substances that are harmful to the user cannot be sold. Hydoquinone is already prohibited for use in cosmetics applied to the skin.
  • The Government intends to apply the Significant New Activity (SNAc) provisions of the CEPA 1999 to hydroquinone. The SNAc provisions would require that the Government be notified of certain proposed new activities related to the substance, and that the new activity be assessed before being undertaken.
  • Information on the risk management actions for hydroquinone is available.

What Canadians can do

  • Canadians who use photographic chemicals should read and carefully follow the safety instructions provided on the label before each use.
  • Canadians who use skin lightening preparations containing 1,4-benzenediol (hydroquinone) should discuss the safe use of the product with their pharmacist and closely follow instructions on the label.

Page details

Date modified: