Mouthwash, cosmetics, and medical devices

MI Free September 21, 2023 5 Comments

A recent case report published in Contact Dermatitis in August serves as a useful reminder of the grey area between cosmetic products and certain medical products / devices or quasi-cosmetic products — and the potential dangers to those with allergies. 

The case concerns an Italian woman who was experiencing oral allergy symptoms — redness and swelling around lips and mouth. Patch testing found her positive to both MI/MCI and several common metal allergens, including nickel. 

Doctors traced the issue to her mouthwash, called Curasept®, which contained isothiazolinone preservatives, and which was marketed not as a cosmetic, but as a ‘medical device’. (Take care with this brand, incidentally, should you come across it. Some of their other oral care products contain MI, such as this toothpaste.)

What’s the difference?
A cosmetic is a preparation which moisturises, conditions, cleans, colours, perfumes or deodorises the part of the body on which it is applied, those parts including all external skin, hair and nails, and the oral cavity. A cosmetic is about improving appearance and condition; it’s about ‘beauty’. Cosmetics are legally bound to follow cosmetic laws, including those introduced with regards to permitted usage (or not) of MI and MCI. 

However, if a preparation serves a medical or ‘lifestyle’ purpose, it may not be classified as a cosmetic, and the associated laws may not apply as far as allergies are concerned. 

Cosmetic vs ‘Medical’ Mouthwash
Cosmetic mouthwash — the sort you might commonly find on a supermarket shelf — will serve only a cosmetic action, such as freshening (ie ‘deodorising’) breath.

But ‘medical’ mouthwash will serve additionally or principally as a curative. In the case of Curasept, this is described as a product for the “treatment of mouth ulcers, gingivitis, periodontitis, receding gums, care after oral surgery and caries”. That is medical, not cosmetic. 

As it happens, MI / MCI are permitted in cosmetic mouthwashes in the UK / Europe because they are ‘rinse off’ (or rinse out!) products, not ‘leave on’ cosmetic products, in which MI / MCI are banned. 

But as the paper in Contact Dermatitis tells us: “the current regulations concerning medical devices do not require the complete declaration of all the ingredients in the label”. 

This is unlike cosmetics, which requires full declaration of ingredients.

You can see how this might be a problem for those with (all) allergies. 

Further examples, and borderline products
Eye drops whose main role is to offer relief to tired or stinging eyes, or indeed for an eye infection, are not cosmetics — but mascara, eye liner and eye cream, all of which enhance the beauty of the eye area, and condition the skin respectively, are.

A vaginal douche is not a cosmetic, but a gentle wash for the vulva is.

Intimate lubricants are not usually classed as cosmetics … 

A hand cream is a cosmetic — as its function is to moisturise — but a hand sanitiser, whose function is to kill or protect from germs, is considered a biocide. However, a moisturising hand gel which also serves as a sanitiser could potentially fall into both camps, in which case it would be prudent to check what the primary purpose of the product is — if cosmetic, it should follow cosmetic laws, but if not, it might not. 

A topical muscle or joint gel for the treatment of pain or stiffness is unlikely to be a cosmetic unless, as above, it also serves a primary moisturising purpose, in which case it should be classed as a cosmetic, and be MI / MCI free in the UK and Europe. 

Medical ointments, for the treatment of eczema, for instance, are definitely not cosmetics, but I’ll return to this subject in a subsequent post. 

The bottom line
In a nutshell, if there is any doubt that a product for use on the body might not be a cosmetic, then remember that it may not be subject to cosmetic laws. 

Important: MI / MCI is banned in the UK / EU in leave-on COSMETICS, not necessarily on all leave-on PRODUCTS. 

In the US, I have found this document from the FDA which touches on this, but I hope to return to this on another occasion. If any US readers can shed further light, please leave a comment. Remember: MI / MCI remains permitted in leave-on cosmetics in the US, though I understand it has now been banned in Canada.