Hair dye safety: EWG cancer risk claims clash with FDA regulatory stance

09 Sep 2024 --- A routine practice for nearly 80% of people worldwide is called into question by the Environmental Working Group (EWG). The watchdog warns of health risks associated with hair dyes and claims US FDA regulations are “falling short.” Personal Care Insights speaks with the agency to learn about hair dye regulation and safety.

Renewed attention on hair dyes and potential risks follows the increased use of products at home during the pandemic. EWG points to research that suggests ingredients used in many coloring products can cause skin irritation or cancer. It emphasizes the risks connected with chemical hair colorants, especially for long-term users and salon workers.

EWG lists what it sees as common ingredients used in hair dyes that can cause skin irritation or cancer: 

• Resorcinol
• M-aminophenol
• Methylisothiazolinone
• P-phenylenediamine
• Undisclosed “fragrance” or parfum 
• Imidazolidinylurea 
• DMDM hydantoin.

Its analysis of 560 hair dyes suggests the prevalence of hazardous ingredients and finds most hair dyes score as moderate hazards, with only 4% receiving the highest safety rating.

Products marketed to Black women often contain more hazardous ingredients, says EWG.Lack of regulation?

The watchdog claims FDA regulation of hair dye products is inconsistent since it approves of color additives in most cosmetics, including coal-tar dyes, and wants the products to carry warnings about possible carcinogenic effects.

The 2022 Modernization of Cosmetics Regulation Act sought to impose stricter regulations on cosmetic products, including safety records and labeling. However, EWG notes that regulatory gaps persist, particularly concerning the disclosure and safety of ingredients in hair dye products.

The FDA responded to our request for clarification. It says the EWG statement about coal-tar dyes not requiring approval by the FDA is accurate but needs to be labeled with a warning. “As we describe in How Safe Are Color Additives?, synthetic organic dyes, traditionally called ‘coal-tar dyes,’ do not need to be approved by the FDA, and listed as color additives in the Code of Federal Regulations (CFR) before being used in hair dye products as long as the product labels include both a statutory caution statement below, alerting the consumer to potential irritation from the coal-tar dye ingredients and instructions for a preliminary skin test (also called a patch test).”

“Caution — This product contains ingredients which may cause skin irritation on certain individuals and a preliminary test according to accompanying directions should first be made. This product must not be used for dyeing the eyelashes or eyebrows; to do so may cause blindness. (Federal Food, Drug & Cosmetic Act, 601(a)).”

Based on this, the spokesperson says EWG’s “statement that coal-tar dyes are exempt from regulation is not accurate. FDA may take action against a coal-tar hair dye product if:

• The product does not have the caution statement on its label or come with adequate directions for a skin test, or
• An ingredient other than the coal-tar hair dye itself is harmful, or
• The product contains an unapproved color additive that is not a coal-tar dye, or
• It is otherwise adulterated or misbranded.”

The FDA adds, as long as the product label has the statutory caution statement and sufficient instructions for customers to conduct a skin test prior to dying their hair, the FDA cannot take action against coal-tar hair dyes on the grounds that they are or contain poisonous or deleterious ingredients that may harm consumers.

“Regarding the potential carcinogenic risks of coal-tar dyes, in the 1970s, some coal-tar hair dyes were found to cause cancer in animals. FDA published a regulation (21 CFR 740.18) requiring a special warning statement for hair dyes containing 4-methoxy-m-phenylenediamine 2,4-diaminoanisole and 2, 4-methoxy-m-phenylenediamine sulfate 2,4-diaminoanisole sulfate,” explains the FDA.

“Although 21 CFR 740.18 was subsequently stayed, the cosmetic industry has since reformulated coal-tar hair dye products, and we are not aware of any current hair dye products that use these two ingredients.”

Cancer concerns

EWG also highlights research suggesting a link between hair dyes and various forms of cancer. It says the International Agency for Research on Cancer (IARC) classifies the workplace exposure of hairdressers and barbers to hair dye chemicals as “probably carcinogenic to humans.” 

The FDA notes a legal requirement to label coal-tar hair dyes, include a caution statement and give consumers directions for performing skin tests before use.The FDA underlines the legal requirement to label coal-tar hair dyes, include a caution statement and give consumers directions for performing a skin test before using the products.

“We maintain several publicly-facing web pages to help inform stakeholders, which includes consumers and manufacturers, about the safety of hair dye use, including Hair Dyes, Hair Dye and Hair Relaxers and Cosmetics Safety Q&A: Hair Dyes.”

“Regarding the risks for salon workers, please note that FDA has authority over cosmetic product safety, but other agencies regulate workplace safety. Occupational Safety and Health Administration regulates workplace safety and National Institute for Occupational Safety and Health researches workplace safety. State and local licensing authorities may also have requirements.”

The EWG says resorcinol, a coloring agent used in hair dye, can cause skin sensitization, endocrine disruption and cancer. P-phenylenediamine, also used as a coloring agent, is banned in European cosmetics due to its links to cancer and other health risks.

The organization also points to the analysis of 42 studies that suggest the longer someone works as a hairdresser, the higher their risk of developing bladder cancer.

Regular users of hair color also run a higher risk. The EWG finds studies linking regular hair dye use to an increased likelihood of cancers, such as uterine and breast cancer, next to the formation of ovarian tumors. Black women appear to be at a higher risk, with research finding a 45% higher breast cancer risk among those using permanent hair dye than among white women.

The EWG notes that apart from cancer risks, hair dyes are also a source of allergic reactions, with a study identifying hair dyes as one of the most common sources of allergic reactions.

FDA says it has no reliable evidence showing a link between cancer and coal-tar hair dyes on the market today.The organization urges consumers to be informed about the potential risks associated with hair dyes, especially as it thinks US regulations are leaving workers and consumers vulnerable. 

Unreliable evidence on coal tar

With increasing evidence linking certain hair dye ingredients to cancer and health risks, we ask the FDA about its plans to reassess and potentially tighten regulations: 

“The FDA takes its responsibility seriously to ensure the safety of cosmetics. FDA evaluates safety using any available data. For example, the Cosmetic Ingredient Review (CIR) Expert Panel is an independent, industry-funded panel of medical and scientific experts that meets quarterly to assess the safety of cosmetic ingredients based on data in published literature as well as some that are voluntarily provided by the cosmetic industry.” 

“FDA takes the results of CIR reviews into consideration when evaluating safety, but the results of FDA safety assessments may differ from those of CIR. At the March 2023 Cosmetic Ingredient Review Expert Panel meeting, the Panel maintained the conclusion that the currently available hair dye epidemiology data do not provide sufficient evidence for a causal relationship between personal hair dye use and cancer.”

However, the agency says it continues to monitor research on hair dye safety and is collecting adverse event data that helps it evaluate the safety of ingredients.

“We do not have reliable evidence showing a link between cancer and coal-tar hair dyes on the market today,” underlines the spokesperson.

By Venya Patel