MI, PPD and Hairdressers …

Given the levels of exposure to cosmetic ingredients which every working hairdresser submits herself to on a daily basis, it’s no surprise that hairdressing is one of the more perilous occupations with respect to allergic contact sensitisation — and severe cases can be career-ending, or at least extremely limiting. 

A new paper has just been published in the journal Contact Dermatitis (click here for the abstract) looking at the levels of allergic sensitisation among female hairdressers — and hair salon customers — drawing from patch-test result data spanning a recent eight-year period. 

The results are extremely interesting, and perhaps not quite what you might expect …



When it came to the very potent hair dye allergens PPD and TDS — both commonly found in permanent hair dye products — it was found that allergy rates among consumers were higher than among hairdressers, with around 20% sensitisation rates among the latter, and around 30% for the former group, for both ingredients. 

Why might this be? I can only guess (not having seen the full paper) that it is because hairdressers are trained to take extreme care with hair dyes. Non-professionals, on the other hand not only experience potentially under-protected exposure at the salon, but might also self-apply DIY hair dye kits at home with even fewer precautions. Despite being exposed to the chemicals perhaps only a handful of times a year, as opposed to constantly throughout a working week, ordinary consumers may well be at greater risk. 



Curiously, MI was also a “notable” allergen highlighted in the research — but on this occasion, it was the hairdressers who were found to have far higher rates of sensitisation than hair salon users — around 10% versus 3%. 

And why might that be? Well, again, I can speculate that hairdressers may not feel the need to (or be trained to) take greater care with exposure to the shampoos and conditioners in which MI (and MCI) are commonly found, possibly not bothering with gloves to wash clients’ hair, as they would certainly with hair dye, wrongly assuming them to be completely ‘safe’. Sensitisation to isothiazolinone preservatives is far likelier with ‘leave on’ products rather than ‘rinse off’, but repeated daily exposures without protective gloves is likely to challenge the immune system of anyone susceptible to allergy, and hence possibly the higher result. 

Although the researchers warn against making direct comparisons, it seems fair to assume that more protection for hairdressers in the working environment is needed. 


Choosing Products

If you’re looking for pointers for PPD-free hair dyes, this article on my general allergy website, Allergy Insight, is perhaps a good place to start. 

An alternative is this article, specifically looking at PPD and MI, which you’ll find on this website, and covers much of the same ground. 

There are a lot of other articles on MI-free hair care products on this website too, for particular needs. You will find collated links plus some fully MI-free brands all provided in this article.

Some of these articles / links haven’t been checked or updated in over a year, so I’ll be doing that in the coming days. Double check any recommendations and please let me know if you spot any issues or broken links, or indeed wish to make some recommendations, which are always welcome.

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