When I typed
significant, thats because thats a little high for a 1 person salon, however its still well below accepted safe levels.
Safe exposure levels generally fall between 50ppm to 100ppm (where 50 is very conservative and actually based on using MMA as a surrogate for EMA).
The average salon is between 4ppm to 10ppm and in severe situations can go beyond 15ppm. Obviously the salons with no ventilation, extraction, and lots of techs not following good practises are going upward of 15ppm. The higher the ppms, their more its going to stink. Saying that, the salon will 'stink' when you are at 0.75ppm (still up to 100 times
below safe levels).
Its good practise to limit your vapour exposure (if only more from a nuisance issue than a serious health concern). That isn't to say that it is impossible to become 'overexposed' to the vapour, just like it isn't impossible to get hit by lightning twice. Impossible? No. Improbable? More so
Be safe and follow good working practise, use adequate ventilation and extraction and finally, don't walk around during thunderstorms with lightening rods
Someone also mentioned independent studies on things like this (don't recall if it was this thread or another). This has been done several times. The most recent CIR (Cosmetic Ingredient Review) study declared that EMA was safer than their own previous studies had determined when used as directed.
Another study was done here in the UK, I just got off the phone with the gentleman that conducted it. He is now looking into getting authorisation to publish the study to the public domain.
Hope this clears the air a little