Three ingredients, three problems …

Three interesting snippets on issues that concern us have come to our attention lately …

The first concerns the preservative methylisothiazolinone (MI) — a subject we have covered extensively before.

Cosmetics Design Europe recently reported that Denmark has called for an EU-wide ban on the preservative because, as their Environment Minister says, “consumers should not be exposed to substances which we know are highly allergenic”. However, such logic would also result in our banning nuts and peanuts, and many fragrances.

The problem, which many cosmetic or dermatological experts have already stated, is that the more preservatives we ban, the more we restrict the available options to formulators — and the more those fewer preservatives will get used, and perhaps overused … with the potential to sensitise more people, and thus further restrict the available preservatives. We’re no fans of MI here, and will do our best to support people with MI-allergy through information and articles, as we have in the past, but banning preservatives is seen by many experts as a slippery slope … and has to be decided on very, very carefully …


The enzyme papain is found naturally in papaya

The second concerns the enzyme papain — derived from papaya, and sometimes called ‘plant-based pepsin’ — which is used by cosmetic manufacturers in products such as facial scrubs, to ‘digest’ away dead surface skin cells. So far, so natural, and so cleansing — but here’s the kicker: papain is a potent allergen, according to this Science Daily report, following a study by researchers at the University of Vienna — who found that it can weaken the skin’s barrier function. Curiously, it retains its allergenicity, even when its enzymatic action is blocked, and it also bears a close structural similarity to house dust mite allergen. Researcher advises that those with sensitive skin and young children avoid it … If this sounds like you, then perhaps check your exfoliating scrubs …

And the third concerns a previously under-recognised fragrance allergen, which is not one of the 26 fragrance allergens (such as geraniol and limonene) which must be listed on cosmetics ingredients when present above certain concentrations. The fragrance allergen is called linalyl acetate, and it is present in lavender. According to a new study in Contact Dermatitis, allergy to this fragrance allergen may effect around 2% of those with contact-dermatitis-related eczema. Should it be added to the 26? Possibly — as we have reported before, many feel that the fragrance allergens should be far more numerous …

All these cases remind us that — whether natural or synthetic — most ingredients used in our cosmetics have the potential to cause us problems such as allergies — even if they only affect a small percentage of the population. It’s a complicated business, and the solution may not be the seemingly obvious one.

Remember too: before self-diagnosing, do see a GP and perhaps ask for a referral for patch testing for contact dermatitis. It’s so easy to get things wrong when you try to work out the cause of your reactions yourself.


  1. lesley

    I have recently been diagnosed as allergic to Methylisothiazolinone and Methylchloroisothiazolinone and am trying to eliminate these products from my house. I have a question : I have noticed that when I buy new leggings I get really itchy on my body and legs, is this product part of the dye used perhaps?
    and is there a comprehensive list of products that are free of these nasty chemicals?

    1. Alex (Post author)

      We have heard reports of this – MI being used in clothing – but haven’t been able to confirm it. It’s worth asking one of the several Facebook groups dedicated to MI. You’ll find them in the resources in this article of mine towards the foot – the article also lists some MI-free laundry products, which you may find useful, in case that’s what the problem might be.


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