Usually associated with
use in skin lighteners, hydroquinone may also be a contaminant in other
cosmetics ingredients. It's one of the worst ingredients used in
personal care products and may disproportionately affect women of color,
who are more likely to be exposed to hydroquinone if they use skin
Products That May Contain Hydroquinone
Hydroquinone is commonly found in products marketed to lighten the skin,
and is one of the most controversial ingredients still used in cosmetics. It is
marketed most aggressively to women of color who also tend to use a
greater number of beauty care products (i,ii). As a result, individuals
who use skin lighteners with hydroquinone may also use other products
with highly controversial ingredients, such as those found in hair relaxers,
hair colorings, nail products and some glues used in hair extensions.
Very little research has explored how the health effects of a single
chemical are increased with exposure to other chemicals, but the
research that has been done suggests that some effects are considerably
In addition to its purposeful use in skin lighteners, hydroquinone may
be an impurity in ingredients commonly found in facial and skin
cleansers, facial moisturizers and hair conditioners. These ingredients
include tocopheral acetate, found in 24.9 percent of products in the
Environmental Working Group's Skin Deep database; tocopheral, found in
12.1 percent of products; tocopheral linoleate and other ingredients
with the root toco.
Hydroquinone works by decreasing the production of melatonin pigments in
the skin. Because the chemical lightens skin by reducing melatonin, it
simultaneously increases exposure to UVA and UVB rays deep in the skin
(iv). This increases skin cancer risks due to UV exposure, in addition
to the carcinogenic effects of the chemical itself. The chemical is
allowed in personal care products in the United States in concentrations
up to 2 percent. Although banned in the European Union, a
UK news report found that products containing hydroquinone were
relatively easy to procure.
The U.S. Cosmetics Ingredient Review Panel indicates that hydroquinone
is unsafe for use in products that are left on the skin (v,vi), but due
to lax enforcement, directions for skin lightening products containing
hydroquinone encourage frequent and consistent use on the skin (vii).
The Environmental Working Group's Skin Deep database, which compares
cosmetic ingredients to more than 50 international toxics databases,
identifies hydroquinone as a carcinogen, immunotoxicant and
developmental and reproductive toxicant, and also identifies concerns
regarding the ingredient's risks for various organ systems, the
endocrine system and neurotoxicity (viii).
In addition to concerns about long-term toxicity, hydroquinone is linked
to a skin condition called ochronosis in which the skin becomes dark and
Skin Deep ingredient information: Hydroquinone
i Malkan, S (2007). Not Just a Pretty Face: The Ugly Side
of the Beauty Industry, pp. 70-71. Gabriola, BC, Canada: New Society
ii MRI Buying Styles Fall 2005; Roper NOP World Health and Beauty Aids
Study May 2005; Yanklevich Monitor Multicultural Marketing Study 2005
(in collaboration with Burrell and Karzenny/FSU), as reported on
iii Gray, J (2008). State of the Evidence: The Connection between Breast
Cancer and the Environment. San Francisco, CA: Breast Cancer Fund.
iv Jimbow, K., Obata, H., Pathak, M. A. and Fitzpatrick, T. B., 1974.
Mechanisms of depigmentation by hydroquinone. Journal of Investigative
Dermatology 62, pp. 436449.
v CIR (Cosmetic Ingredient Review Expert Panel) Final report on the
safety assessment of t-butyl hydroquinone. 1986.Journal of the American
College of Toxicology 5, pp. 329351.
vi CIR (Cosmetic Ingredient Review Expert Panel) Final report on the
safety assessment of t-butyl hydroquinone, 1991. Journal of the American
College of Toxicology 10, pp. 17.
vii Environmental Working Group. Skin Deep. Product search for
Physicians Complex 6% Skin Bleaching Cream owned by CosMed. Online at
www.cosmeticsdatabase.com. Accessed July 23, 2008.
viii Environmental Working Group. Skin Deep. Hydroquinone. Available
Accessed December 9, 2008.
Burkhart CG (2007). Ochronosis. Emedicine. http://www.emedicine.com/DERM/topic476.htm.
Accessed July 23, 2008.