EU-banned Substances Found in 5 Anti-dandruff Shampoo Models Manufacturer Urged to Review Formula and Improve Labelling to Protect Consumer Rights

Dandruff problems could cause distress and embarrassment, thus many consumers turn to anti-dandruff shampoo in hopes of easing the symptoms. However, dandruff may be due to a myriad of causes, such as skin dryness, excessive sebum production, or even related to common skin condition such as seborrheic dermatitis. Consumers should first look into the root cause before selecting suitable products to address their problem. For anti-dandruff shampoo to achieve the desired performance, the anti-dandruff active ingredients must reach a certain concentration, yet the various active ingredients also have different types of health risks. In the Consumer Council’s test on 25 models of anti-dandruff shampoo on the market, 4 models were detected with zinc pyrithione (ZPT), which has been prohibited by the European Union’s (EU) Cosmetics Regulation, at concentrations ranging from 0.19% to 0.95%. ZPT is permitted by the United States Food and Drug Administration (US FDA) for use as an active ingredient in Over-the-Counter (OTC) drug products[1], and the levels of ZPT found in the Council’s tested models also complied with the requirements of the Mainland’s Safety and Technical Standards for Cosmetics. ZPT is an anti-dandruff ingredient with antibacterial properties. However, animal studies have shown ZPT may damage the unborn child, while studies have also shown that it could cause allergic contact dermatitis, as well as irritation if it gets into the eyes. 10 models were detected with another active ingredient salicylic acid, one of which had a concentration as high as 1.9%, which may be categorised as an OTC drug if sold in the US, yet the majority of the models with salicylic acid as a labelled ingredient did not carry the warning label “not to be used for children under 3 years of age” in accordance with EU requirements. The test also found fragrance allergens in over 90% of the models, of which 2 were even detected with fragrance allergen butylphenyl methylpropional (BMHCA), which was banned in EU due to its reproductive toxicity. Furthermore, 8 models were found with galaxolide (HHCB), which is not only allergenic, but also highly toxic to aquatic life and not readily biodegradable, possibly posing negative impact to the marine ecosystem in the long run. The Council urges manufacturers to proactively review their product formulae and avoid using chemical substances that have been prohibited internationally, instead switching to ingredients that are harmless or less harmful to the environment. At the same time, they should enhance the transparency of labelling information to help consumers address dandruff concerns.

The Council tested 25 models of anti-dandruff shampoo ranging from $50 to $430 per bottle, equivalent to unit prices of around $0.67 to $19.55 per 10ml or 10g, a difference of over 28-fold. All models carried “anti-dandruff”, “dandruff relief” or “anti-flake” claims, while 1 model also claimed to control symptoms of seborrheic dermatitis. The test covered 4 anti-dandruff active ingredients, including ZPT, piroctone olamine, climbazole, and salicylic acid, as well as chemical safety. Among the 25 models, 3 were not found with the 4 active ingredients, of which 2 models claimed to have added herbal ingredients to achieve anti-dandruff efficacy. The remaining 22 models were detected with 1 to 3 types of active ingredients. As the causes for dandruff can be complex and vary among individuals, while the formula and synergism between ingredients also differ between products, the current test did not grade the models based on their dandruff removal performance.

4 Models Contained ZPT Potentially Damaging Unborn Children

Salicylic Acid Content of 1 Model Reached the Specified Level Which May Be Categorised as OTC Medicine in the US

ZPT could inhibit the growth of Malassezia, a fungus which causes dandruff, thus reducing the formation of dandruff. However, ZPT is an eye irritant. Animal studies have shown ZPT may damage the unborn child. Jurisdictions around the world have imposed different regulations on the use of ZPT. The European Chemicals Agency (ECHA) classifies ZPT as a CMR^[2] 1B substance — “Toxic to Reproduction”. In 2020, the Scientific Committee on Consumer Safety (SCCS) considered ZPT as “safe when used as an anti-dandruff in rinse-off hair products up to a maximum concentration of 1%”. However, the SCCS opined that since it has not demonstrated that there are no suitable alternative substances available, ZPT did not meet the conditions to be exempted as a CMR substance. As such, ZPT has been prohibited for use in cosmetic products since March 2022. On the other hand, the US regards ZPT as a permitted ingredient in OTC drug products, with a regulated concentration from 0.3% to 2% depending on its intended use; whereas in the Mainland, the Safety and Technical Standards for Cosmetics sets an upper limit of 1.5% for ZPT in “anti-dandruff rinse-off hair products”. The Council’s test found ZPT in 4 models ranging from 0.19% to 0.95% in detected levels, which complied with the limit set out in the Mainland’s Safety and Technical Standards for Cosmetics.

Although piroctone olamine could irritate the skin and may cause serious eye damage, owing to its relatively lower toxicity than ZPT, it has gradually become an alternative for ZPT and is presently a common anti-dandruff active ingredient. According to EU and Mainland regulations, piroctone olamine has been approved for use as a preservative at a maximal concentration of 1.0% in cosmetic rinse-off products. Piroctone olamine was found in 13 models, ranging from 0.066% to 0.86% in concentration, all in compliance with relevant EU and Mainland regulations.

Despite the fact that salicylic acid could improve dandruff problems by acting as a keratolytic agent to loosen the scales and enabling them to be washed off, it does not actually cure the relevant dermatitis or conditions. Among the 10 models detected with salicylic acid (concentrations from 0.087% to 1.90%), the model with the highest concentration met the specified level set by the US FDA for the related OTC drug products. In other words, if this product is sold in the US market, it may be categorised as an OTC drug product.

Over 90% Models Contained Fragrance Allergens

2 Found with Prohibited BMHCA

Fragrance ingredients are widely used in cosmetic and skincare products to cover the unpleasant odour of the raw ingredients and to enhance consumer appeal and sensation. The test found that over 90% of the models (23 models) were detected with 1 to 7 types of fragrance allergens, with amounts ranging from 0.0011% to 0.43%. The model with the highest total amount of fragrance allergens was as high as 0.4515%, with limonene and linalool being more common. 2 models were detected with the EU-banned BMHCA at concentrations of 0.0038% and 0.0040% respectively. BMHCA has reproductive toxicity and has been shown to have adverse effects on the sexual function and fertility in adult experimental animals.

4 Models Lacked Warning Labels for Salicylic Acid

13 Had Incomplete Labelling of Fragrance Allergens　

As individuals with dandruff problems may already have allergic conditions on their scalp, the transparency of product information is paramount, so as to prevent consumers from using unsuitable products by mistake. However, the test revealed much room for improvement in terms of the labelling in many models. According to EU requirements, products containing salicylic acid must be labelled with the warning “not to be used for children under 3 years of age”, but among the 5 models with salicylic acid as a labelled ingredient, only 1 carried the relevant warning, another was labelled as “product intended for adult use only”, while the remaining 3 did not have any relevant warnings. In addition, among the 21 models found with 1 to 5 types of fragrance allergens at levels higher than 0.01%, 13 models were not labelled at all or were only labelled with some of the fragrance allergens. The Council opines that although Hong Kong currently does not require cosmetic products to be labelled with detailed lists of ingredients or list out the allergenic substances, in order to safeguard the safety of consumers, manufacturers should make reference to the latest international regulations and proactively enhance their product formula and improve the labelling information. They should also refrain from using chemical substances which have been prohibited for use among international regulations, and remind consumers of relevant allergenic risks.

5 Models Found with Climbazole and 8 with HHCB

Posing Long-term Environmental Impact

Some anti-dandruff active ingredients and fragrances have health risks and may impact the environment. 5 models contained the anti-dandruff active ingredient climbazole, the detected levels (0.048% to 0.45%) falling within the permitted range of the EU and Mainland regulations, but ECHA stated that climbazole may disrupt the endocrine system in fish, posing significant aquatic toxicity. As climbazole is not readily biodegradable, daily use of shampoo containing climbazole may continuously release the substance into the environment via wastewater, which may contaminate the food chain. Meanwhile, 2 other active ingredients ZPT and piroctone olamine are also harmful to aquatic life.

Synthetic musks are often used as a fragrance ingredient in personal care products. HHCB was detected in 8 models with concentrations ranging from 0.0025% to 0.160%, of which 6 models had detected levels exceed 0.01%, reaching the EU concentration^[3] requiring relevant labelling, yet the models were not labelled with relevant information. HHCB is highly toxic to aquatic organisms and could accumulate in the natural environment, eventually contaminating the food chain. Although there is currently no regulation for synthetic musks in Hong Kong, the Council recommends manufacturers to be mindful of the ecosystem and environment during their business operations, and endeavour to use more eco-friendly fragrance ingredients.

Advised to Determine the Root Cause to Select Suitable Products

The cause of dandruff varies from person to person. Consumers are advised to understand the cause of their dandruff problem before selecting and using anti-dandruff shampoo, so as to avoid using unsuitable products which may aggravate the problem. Consumers should also take preventative measures to take care of their scalp regularly, including:

• Select appropriate products based on the scalp and hair type, and consider switching shampoos according to changes in the weather, such as using products with better oil control during summer, and opting for more moisturising products in winter;
• Avoid using excessively hot water for washing hair, and refrain from scratching the scalp with fingernails as it may cause wounds and infection. Rinse hair thoroughly after using hair products;
• Minimise use of hairstyling products and hair dyes, as the irritating ingredients may increase dandruff formation; also reduce the use of products containing alcohol or greasy haircare products.

Consumers may refer to the following tips when purchasing and using anti-dandruff shampoo:

• Carefully review product labels before purchasing, and avoid products with highly allergenic ingredients such as fragrance allergens, methylisothiazolinone (MIT) and methylchloroisothiazolinone (CMIT), especially for individuals with eczema or skin allergy;
• Use according to the instructions, including the usage frequency and amount, and the duration of leaving the product on the scalp;

If symptoms do not subside after using anti-dandruff shampoo for a period of time, or if redness or swelling of the scalp occurs, one should seek medical advice to address the problem.