Methylisothiazolinone
(MI) is listed in Annex V/57 of Cosmetic Regulation 1223/2009/ECC to be used as
preservative at maximum concentration of 0.01% (100 ppm),
and in
Annex V/39 in the mixture of Methylchloroisothiazolinone (MCI) and
Methylisothiazolinone (MI), currently allowed as a preservative in all
cosmetics at a maximum concentration of 0.0015 % (15ppm) of a mixture in the
ratio 3:1 of the two substances.
Several
Member States raised concern on the use of Methylisothiazolinone as data
demonstrates that it is a sensitizer in animals and a contact allergen in
human, particularly with sensitization in young
children from moist toilet paper/hygiene moist tissues or cosmetics.
EU Commission requested a reassessment of the
safety of MI when used as preservative in cosmetics at maximum concentration of
100 ppm.
Current clinical
data indicate that this concentration of MI in cosmetic products is not safe
for the consumer.
SCCS
concluded that for leave-on cosmetics
(including ‘wet wipes’), there is no
adequate information to suggest a safe dose of MI from the view of induction of
contact allergy.
For rinse-off cosmetics, it may be
considered that circa 3.8 ppm MI (as in the MCI/MI mixture) is acceptable as
this is the amount present when MCI/MI (3:1) is used at 15ppm for preservation
of rinse-off cosmetic products, but it is unknown whether this concentration
provides useful preservative activity.
However,
as MCI is a more potent allergen than MI
and is the principal moiety in MCI/MI, SCCS suggests that MI should be safe in
rinse-off cosmetic products at 15 ppm (0.0015%). Permitted levels of MI in
rinse-off cosmetics should be safe for previously sensitised
individuals but whose allergy has not been shown by formal investigation.
Moreover, MI should not be used as an addition
to a cosmetic product already containing MCI/MI.
More
frequent review of data to monitor sensitisation frequencies of MI and related
isothiazolinone preservatives is recommended.
Labelling
is only helpful to a consumer who has a known (established by diagnostic patch
test investigations) allergy. It is unknown what proportion of the general
population is now sensitized to MI and has not been confirmed as sensitized.
Since
MI is widely used in other consumer products (eg. detergents, paints), exposures
from such sources should also be assessed.
