methylisothiazolinone allergy
Beauty, Latest Posts, Lifestyle

What’s in Your Make-Up: The Rise of Methylisothiazolinone Allergy

It started with an irritating itch. Initially, it was just the hands, but in a matter of weeks, the itch had spread to my legs, my back, my whole body. My body was a bloody, scabby, blistering, oozing mess and no matter what I did about it – no matter how much moisturising or anti-itch cream, it just wouldn’t go away.

Initially I was diagnosed as having adult atopic eczema. Apparently, it’s pretty common to experience it as a child, then go into remission throughout your teenage years, only to re-emerge in young adulthood.

Prescribed a hefty course of steroids and equipped with a steroid cream, my skin seemed to recover. But this was to be short lived – the cream merely acted as a plaster. The cream, instead of treating sporadic patches effectively, was instead firefighting a losing battle. Within months, I was back to square one – in the height on my discomfort, resorting to wearing cotton gloves during the day whilst I typed, and at night to stop me scratching. I was utterly miserable.

Eventually, a patch allergy test conducted by a dermatologist revealed that I was indeed extremely allergic to many substances – but most notably, the controversial additive Methylisothiazolinone.


What is Methylisothiazolinone?

Methylisothiazolinone, or MI, is a preservative. MI is a relatively new chemical for consumers. Historically, the preservative was typically used for industrial or occupational uses, however sometime between the early to mid-2000s, it became a choice preservative for consumer goods: household cleaning products, soaps, deodorant, glue, cosmetics* – the list is extensive. The purpose of MI is to prevent or reduce the growth of unwanted bacteria.


We all have allergies. What makes this one so special?

Statistically, the chances are you probably have an allergy or an intolerance to something. For some, it’s a life threatening allergy to nuts, for others, it’s big puffed up eyes from using make up wipes. Allergies are a fact of life, and when handled with the right treatment and proactive care, many can live a totally normal life.

But here’s the problem with Methylisothiazolinone: despite the fact it affects a significant number of people, it doesn’t get the air time it needs to make the public aware. Medical professionals are largely in agreement that the number of people who are reporting allergies to MI are on the rise – some going as far as to call it an “epidemic.” , some going as far as to call the European Commission negligent.

How common is it? The numbers vary depending on the outlet or publication reporting, but studies suggest that between 11% and 27% of people tested for general skin allergies can show a positive reaction to MI. To put that into perspective: that’s in some cases almost a third of people tested.


Who are the biggest offenders?

Since being diagnosed with a Methylisothiazolinone allergy, I’ve become only too aware of how many big brand companies are using the preservative. Once I stopped using these products, my symptoms (and my misery) disappeared within a matter days.

What’s perhaps more surprising though, is the number of “skincare” or “sensitive skin” products that also contain the preservative – leaving choice to be very limited.

The names of some of the worst offenders may surprise you, such as Boots (own brand) and Nivea.


I want to avoid Methylisothiazolinone. What can I do?

Once you’ve been formally diagnosed, your doctor will equip you with a boat load of information. Most of it will be geared around avoidance.

Your first port of call should be to review everything you use on a daily basis – from foundation to washing up liquid. Anything that comes into contact with your skin, however little,  is suspect – so check yourself as you move about your daily routine.

When it comes to shopping for suitable products, be cautious. Brands that make 100% “natural” or hypoallergenic claims aren’t always what they seem and often products are loaded with harmful “naturally” occurring substances, including Formaldehyde, a well-known carcinogenic.

Methylisothiazolinone is present in so much, you may find adapting to your new lifestyle a little bit overwhelming. However, we thankfully are living in a much more consumer-conscious society – and given enough pressure, it’ll only be a matter of time before brands follow suit.

Do you suffer with an MI allergy? We want to hear about your experience. Leave a comment or join us over on Twitter!

Marketer by day, cake monster by night. Laura is a self-confessed crazy cat lady. She believes there's nothing better than a great pair of leather loafers.


  • Really good to get exposure for this issue and see it being covered here. Just a few corrections: in the UK/EU ‘leave on’ cosmetics (face creams, make-up) are not permitted to include MI in the ingredients, so those products should be safe (unless you have products bought before the ban earlier this year). While I agree that a high percentage of those tested for MI will show a positive reaction, we must bear in mind that this does not represent the general public – but those with suspected allergies / eczema, around 10% or more of which may have MI allergy. Curiously, MI has been around since the mid 80s: there was a previous epidemic, before the current one. I agree with you regarding ‘natural’ ‘sensitive skin’ and ‘hypoallergenic’ claims – that’s no guarantee of safety as far as MI is concerned, and vital to emphasise this point. Well done on raising awareness, and glad you’re improving.

    Alex Gazzola

    • Hi Alex,

      Thanks so much for stopping by. I’ve not heard of the recent ban and have come across some products recently that contain MI, so I’d be interested to find out more and update this article.

      I agree about the general public – as mentioned in the blog, the people who were tested came from a dermatology publication, so one would assume that there were some pre-existing allergies. I definitely think more study needs to go into this – and the potential long term impact.

      I’m interested to hear about your thoughts on the previous epidemic – the nurse that ran my tests actually discussed an earlier epidemic and said to counteract this, they actually increased the amount of MI in industrial products?

      Great site with MI-free – I’ll be visiting often! L x

  • Thanks Laura. Funnily enough, I’ve been researching the previous epidemic and regulations as I’m writing an ebook on MI, and the picture is very complicated. Simply, they did increase the amount of MI permitted, because they originally suspected that MCI (a related preservative – methylchloroisothiazolinone) was the real ‘baddie’ – the first preservative used was a mix of MI and MCI. So, suspecting that MCI was the cause of allergy, they allowed MI on its own to be used, when originally it wasnt’. Trouble is, MI is weaker, so had to be used in greater concentrations … and that appears to have triggered the second epidemic.

    Regarding industrial products specifically, I think it was allowed a little earlier in those, but unsure. The problem with this, of course, is that using MI in both cosmetics and industry and household products as meant our exposure to it can sometimes be great. It’s not ideal.

    Do let me know if you find any ‘leave on’ products with MI in them in the UK – shouldn’t be happening any more.

    All the best, Alex

    • That’s really interesting! I also avoid MCI but I do find it considerably easier to avoid.

      I’ve got a lovely burn like reaction on my hands just now thanks to a soap I came into contact with – it’s a challenge when you have to use public facilities like toilets! I understand that preservatives are a necessary evil for some things – and I’m glad to see much less formaldehyde being used in products – but, even the most recent case of the Johnson and Johnson debacle proves that we sometimes don’t know the long term impacts of chemicals until it is too late!

      I will definitely keep an eye out – I know there are a few “leave in” conditioners I passed on recently because of MI! Stay in touch and do let me know when that e-book goes live – I’d love to have a read.

      L xx

  • I have an aunt who is suffering terribly from the effects of this chemical. She was eventually fortunate enough to find a doctor who is a skin specialist who was able to diagnose her problem. She has suffered for some time now, is in her 80’s and it’s all over including in her head. The itch, pain and heat are terrible. We live in Australia where there is not much recognition of it or what it’s being used in. My aunt has removed the products from her life where she is aware and this has not alleviated the problem, although in the beginning it did begin to improve then reverted after a while. Perhaps her age and length of time in her body may have made it worse.

    • Susan, I am so sorry to hear about your aunt’s suffering! I remember just how miserable I felt when I was in the height of my MI nightmare! It’s worrying that it improved and then returned – does she review her products often? I find that I have to check every now and then to make sure that nothing has changed! L x


Write a comment