Study on methylisothiazolinone in shampoo lacks a credible scientific basis

Consumers can rest assured that their cosmetic products, including shampoos, are safe. The abstract on Methylisothiazolinone (MI), presented at the Cell Biology 2004 meeting of the American Society for Cell Biology, lacks a credible scientific basis in suggesting that MI could be a safety issue for consumers using personal care products. In determining the safety of any ingredient, a major factor is exposure.

Cosmetic exposure is so much lower than what is presented in this abstract as to make the study meaningless for safety evaluation purposes regarding cosmetic products.

The experiments conducted with MI on extracted rat nerve cells in laboratory containers do NOT remotely resemble the possible consumer exposure to this preservative. In fact, safety testing with animals has demonstrated that application of MI does NOT result in systemic toxicity to the preservative. Clinical and functional effects on the nervous system have NOT been observed in relevant safety tests.

MI is a preservative that has been specifically approved for use as a biocide by the U.S. Environmental Protection Agency (EPA), by Japan, and by the European Commission for use in cosmetics. It is used at very low levels, parts per million (one part per million = one drop in a 55 gallon drum) in cosmetic products, including shampoos and other products. MI was reviewed by the Cosmetic Ingredient Review (CIR) in 1992 as a component of a preservative mixture with methylchloroisothiazolinone (MCI) and found to be safe for use in cosmetics.

Cosmetics are regulated under the Food, Drug and Cosmetic Act, which is enforced by the U.S. Food and Drug Administration (FDA). The Food and Drug Administration (FDA) has abundant legal authority to regulate the safety of cosmetic products.

The charge to CIR, an independent scientific body, is to look at all available data and assess the safety of ingredients used in cosmetics. The deliberations are completely open and in public, and the Food and Drug Administration and the Consumer Federation of America both have liaison members who participate in the deliberations of the Panel. Additionally, anyone from the public who has information can offer it for consideration.

The Cosmetic, Toiletry, and Fragrance Association (CTFA) is the national trade association representing the cosmetic, toiletry, and fragrance industry. Founded in 1894, CTFA has an active membership of approximately 275 companies that manufacture or distribute the vast majority of finished personal care products marketed in the United States. CTFA also includes approximately 275 associate member companies, including manufacturers of raw materials, trade and consumer magazines, and other related industries.


  1. Fee Berry Fee Berry United Kingdom says:

    Along with many thousands of others, I have started to suffer from eczema, after being eczema-free for 53 of my 56 years, I have tracked down the culprit:  Methylisothiazolinone.  I have contacted the manufacturers of a number of products which have adopted this chemical as a preservative, and they tell me that scientists tell them that it is perfectly acceptable and harmless in a rinse-off product.  Forget that... I know that's not true.  MI in my shampoo gave me eczema across my eyelids.  Me, my sister, my cousin, my friend... I think the explosion of dermatitis caused by these chemicals is going to affect many people, especially those who look like car crash victims after contact with premises that have been painted with an MI containing paint.  I think you had better take your smug assurances and get back to the laboratory and find out what's going on.  Before a horde of angry consumers put companies which include these chemicals out of business by refusing to buy them.

  2. Dana Todd Dana Todd United States says:

    There has been abundant research in the 11 years since this was written, and an EU commission has now rules that there is no level of MI/MCI that can be proven not to be a sensitizer. It's banned in leave-on products and there is a directive to lower acceptable amounts in wash-off products. However, there is unfinished business in looking at industrial use where consumers can't limit exposure or where it's not labeled such as in paint or leather treatments.
    You can see a large body of the medical and scientific research here

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
You might also like...
Exploring 'food noise': Study sheds light on eating thoughts and obesity treatment breakthroughs