Methylisothiazolinone (MI / MIT) & Methylchloroisothiazolinone (MCI / CMIT): Problem Preservatives

In 2013, one of the biggest stories in skincare health concerned the preservatives MI & MCI, which became notorious after it was found that they were to blame for a worrying increase in skin sensitivities. Alex Gazzola rounds-up the latest news — including recent calls and recommendations for a ban

In July 2013, The British Association of Dermatologists (BAD) and the British Society of Cutaneous Allergy (BSCA) issued warnings of a new potential contact allergy epidemic to two chemical preservatives used in cosmetics, toiletries and household products — methylisothiazolinone (MI or MIT) and methylchloroisothiazolinone (MCI or CMIT).

A blend of the two preservatives, sometimes referred to as Kathon CG, was previously more common, but earlier concerns over MCI meant that in recent years, manufacturers have increasingly taken to using MI alone, and in higher concentrations, which may at least partly explain the recent rise in reported reactions.

The Leeds Centre for Dermatology reported a rise of 6% in contact allergy to MCI/MI and MI over the previous three years. The European Society of Contact Dermatitis (ESCD) was also concerned, writing to the EC to call for an investigation into safe levels.

Dr John McFadden, Consultant Dermatologist at St John’s Institute of Dermatology said at the time: “We are in the midst of an outbreak of allergy to a preservative (MI) which we have not seen before … Many of our patients have suffered acute dermatitis with redness and swelling of the face. I would ask the cosmetics industry not to wait for legislation but to get on and address the problem of MI allergy before the situation gets worse.”

The issue received widespread media coverage, including in The Mail. It was highlighted that the preservatives can be present in wet wipes, cleansers, deodorants, gels, suncare products and shaving foams, as well as household cleaning products.

Some cosmetics companies were swift to act. Johnson and Johnson announced it would remove MI from their Piz Buin sun lotion, as reported in Cosmetics Design Europe. Others are known to be following suit.

Call for a ban

In December 2013, Cosmetics Europe, the European cosmetics trade association, following discussions with the ESCD, issued a statement recommending that “ … the use of methylisothiazolinone in leave-on skin products including cosmetic wet wipes is discontinued. This action is recommended in the interests of consumer safety in relation to adverse skin reactions. It is recommended that companies do not wait for regulatory intervention under the Cosmetics Regulation but implement this recommendation as soon as feasible.”

The Cosmetic, Toiletry and Perfumery Association (CTPA) had initially emphasised the safety of MI / MIT, and called calls for a ban ‘alarmist’ in July — though their statement appears to have since been removed from their website. In December, they reported the news of the European industry recommendations to their members and readers, and sensibly reminded consumers that patch testing was essential for a correct diagnosis (for further information on this, see our article on Contact Dermatitis here).

Skins Matter’s View …

As we blogged at the time, this is a story about allergy to preservatives — not toxicity. Unless you react to them, there is no immediate urgency to avoid contact with the preservatives — unless you are also sensitive / allergic to other skincare ingredients, or have a history of atopy, and therefore may be at slightly increased theoretical risk of developing a future sensitivity to MI. Many, of course, may choose to do so regardless and play safe; given there are alternative products out there with preservatives that seem to be less reactive, this may be a sensible course of action.

There has been some alarmist response to the situation, including a petition that speculates of a link to cancer, and makes a widely repeated error that allergy to MI affects 10% of the general population — it actually has been found to affect 10% of those with eczema who are referred to dermatologists.

Although the matter is obviously a subject of concern, there is a very considered and more sceptical look at the whole saga at the excellent Colin’s Beauty Pages blog, where the eponymous author, a cosmetic scientist, argues that we could be at risk of losing a (mostly) safe and effective preservative that regrettably some people do react very badly to, but nowhere near as widely as has been reported by some.

Nevertheless, it seems highly likely that legislation will follow — though this could take some years to be formalised. Many manufacturers will change formulations in the interim — but again this can take time. It’s likely that we will continue to encounter the ingredients — and reactions to them — for a while.

And, of course, the recommendation only concerns ‘leave on’ products such as moisturisers, at least for now. Dr David Orton, President of the British Society of Cutaneous Allergy, commented: “This recommendation falls short of calling for the removal or a reduction of MI levels in rinse-off cosmetics, such as shower gels or shampoos. We still have concerns that its continued use at present concentrations in such products will elicit allergic reactions in those that are already sensitised. This is a matter which we are hoping to reach agreement on in future planned discussions.”

Many natural and ‘free from’ companies have taken to social media to confirm that they do not use the ingredients in any of their products, and to our knowledge none of the companies we have featured on this website do so. Both MI and MCI are excluded from our Free From Skincare Awards.

That said, this is not necessarily the case with natural or eco household products. For instance, many Earth Friendly Products — such as laundry liquids and dish washes — contain methylisothiazolinone. Some recommended household goods free of MI and other isothiazolinones are listed on my blog, Methylisothiazolinone: Problem Preservative.

We are still keen to hear your experiences. Those of many of our regular readers are adding up steadily at our blog on this subject — many of which are worrying, but some of which do have positive resolutions. Read them here, and do add yours too.


Methylisothiazolinone Free — information site
Methylisothiazolinone Victims — Facebook group