Cosmetic preservative: Allergic risk from chlorphenesin

What is Chlorphenesin?

Chlorphenesin is a synthetic preservative that is often used in cosmetics made in Japan and abroad. It is used in a wide range of products, including:

• Foundation
• Eyeshadow
• Sheet Mask
• Hair Care Products
• Lotion and milky lotion
• Face cream
• mascara

Chlorphenesin prevents the growth of fungi and microorganisms, prevents color change, stabilizes the pH level, and prevents separation of ingredients.

Safety of chlorphenesin

People with sensitive or dry skin tend to be more likely to develop skin irritation, especially eczema. Research has shown that it can be particularly irritating to people who are allergic to preservatives.

Caution should also be exercised when used near infants and young children.
There have been cases where a cream containing chlorphenesin and phenoxyethanol that breastfeeding mothers apply to their nipples has caused breathing difficulties, vomiting, and diarrhea in infants. Based on this, it seems advisable to check whether products that small children may accidentally ingest contain these compounds.

Is it irritating to the skin?

In an irritation patch test conducted on 584 people allergic to preservatives, benzalkonium chloride and chlorphenesin were found to be the most irritating.

Additionally, among 30 subjects without preservative allergies, eight had positive reactions at a concentration of 0.5% chlorphenesin.

Cases of allergic reactions to chlorphenesin

A 38-year-old woman presented with widespread acute dermatitis.

After using the powder and cream, the woman developed a rash all over her body, including her feet, forearms, and hands. Patch tests of the ingredients in the products showed a positive reaction to a 1% solution of chlorphenesin in petrolatum.

A 60-year-old woman with atopic dermatitis

A rash appeared on the face within hours of applying foundation containing chlorphenesin. An allergic reaction was observed to petrolatum containing 1% chlorphenesin.

Moisturizing cream containing chlorphenesin causes eczema on face

A 33-year-old woman had been using a moisturizing cream containing chlorphenesin for one month when she developed eczema on her face, which gradually spread to her entire face, neck, upper chest, and upper arms.
The woman had no history of atopic dermatitis, and a patch test showed a positive reaction to petrolatum containing 1% chlorphenesin.

Rashes caused by ointment containing 0.5% chlorphenesin

Next, a 24-year-old man applied 0.5% chlorphenesin ointment to his feet twice a day to relieve itching. After 29 days, he developed a symmetrical rash on the top of his foot. It then spread to his ankles and arms within 24 hours. Patch testing showed a positive reaction to 0.5% chlorphenesin and the ointment.

Erythematous eczema caused by moisturizer

A 43-year-old woman applied a moisturizer containing chlorphenesin to her face. After application, she experienced a hot, uncomfortable sensation on her face and developed erythematous eczema.
The woman had a history of hay fever but no history of allergies to medicines or cosmetics. Patch tests showed a positive reaction to chlorphenesin.

What are the compounding regulations in Japan?

In Japan, there are regulations that limit the amount of chlorphenesin used to be 0.3%. In the above case, an allergic reaction occurred at a concentration of 0.5% or more. Therefore, there may not be any need to worry excessively.

However, cosmetics are used almost every day. There are some concerns about continued use over a long period of time. People with sensitive skin should be especially careful.