It is the policy of this blog to provide you with sufficient information so that you can decide whether or not you want to use a product that contains Methylisothiazolinone (MI).
What is it?
MI is a preservative and a biocide. It’s used in:
- Industrial products (paints, adhesives, varnishes),
- Household products and
- In the USA and India, its also used in
- Cosmetics,
- Shampoos, and
- Sunscreens.
A bit of history…
Until 2000, MI was used with a related compound Methylchloroisothiazolinone (MCI) in very low concentrations (e.g) 1.8 parts per million in leave-on cosmetic products. However, as soon as it was permitted for use in cosmetics, the levels increased to 100 parts per million.
What did the EU do?
The EU’s Scientific Committee on Consumer Safety collated clinical data, which showed that in a number of EU countries, individuals (including children) were increasingly becoming more sensitive to MI. Some of the EU countries were Denmark, Finland, Germany, France, Portugal, Sweden, and the UK.
One of the problems with sensitisation to a preservative – even through normal contact – is that it may cause allergic contact dermatitis.
Unsurprisingly, the EU banned MI in leave-on cosmetic products.
For rinse-off cosmetic products (e.g.) shampoos, the concentration was limited to 15 ppm (0.0015% or 15 parts to a million).
What did the US do?
It appears that around about the same time, contact allergen cases to MI in the USA were also increasing. In fact, the American Contact Dermatitis Society named MI as contact allergen of the year in 2013.
In February 2020, the USA Cosmetic Ingredient Review published a report that effectively said:
- We won’t ban MI from cosmetic leave on products.
- We get that our approach is contrary to the EU, but essentially
“Instead of banning ingredients that may pose a risk under certain conditions, the Panel has proposed that such risk mitigating tools and strategies be applied by formulators and those avoid exhausting the available preservative systems…”
I don’t understand this approach: there is no contrary data contradicting the European Union approach. Secondly, the EU doesn’t think there is a lack of other preservatives, why does the US?
As I said to an ex-boyfriend recently, “stop coming up with lame assed excuse” for being a jackass. This so applies here.
My approach: I am going with the EU, which bans MI from leave-on cosmetic products based on actual clinical data that it is a contact allergen that can at the very minimum, cause allergic contact dermatitis.
Sources and uses
Castanedo-Tardana M P, Zug K A. Methylisothiazolinone (2013) Dermatitis 24: 2-6
Methylisothiazolinone named contact allergen of the year
SCCS/1521/13 (Revision of 27 March 2014) OPINION ON Methylisothiazolinone (P94) Submission II (Sensitisation only)
Cosmetic Ingredient Review, Amended Safety Assessment of Methylchloroisothiazolinone and Methylisothiazolinone as Used in Cosmetics (February 25, 2020)