Parabens
Uses
This group of chemicals are used as preservatives
in cosmetics, and are antibacterial agents in some antibacterial
toothpastes. Four main parabens are in use: methyl, ethyl, propyl
and butylparabens; many products will have 2 or more of these
chemicals as part of a preservative system. As preservatives
in cosmetics are on the label in the EU it is easy to find out
which products contain these chemicals.
Oestrogenic effects
In late 1998 John Sumpter's group at Brunel
University, UK, published a paper identifying parabens as oestrogen
mimics (Routledge et al., 1998). The authors state:
"Given their use in a wide range
of commercially available topical preparations, it is suggested
that the safety in use of these chemicals should be reassessed,
with particular attention being paid to estimation of the actual
levels of systemic exposure of humans exposed to these chemicals.
The acquisition of such data is a prerequisite to the derivation
of reliable estimates of the possible human risk of exposure
to parabens."
In a screen with a human estrogen receptor
expressed by yeast cells the potency of the parabens group was
butylparaben>propylparaben>ethylparaben>methylparaben.
When methylparaben and butylparaben were injected into immature
or ovariectomized rats, butylparaben led to an increase in uterus
weights (an oestrogenic effect), whereas methylparaben had no
detectable effect.
Another study examining effects on excurrent
ducts of the rat testis through puberty to adulthood found no
effects from butylparabens (Fisher et al, 1999); however this
used much lower doses than the Routledge work.
Industry response
The European Cosmetic Toiletry and Perfumery
Association COLIPA stated that the Routledge work was 'irrelevant'
as 'Parabens are hydrolysed in the skin and we have data to show
that none are entering the blood stream', and said that the Industry
had no plans to follow up the work.
Professor Sumpter replied that
'What we really want to know is what
effects may come from low exposures over a long period of time.
That is the realistic exposure mechanism' (ENDS, 1999a).
AstraZeneca toxicologist Dr John Ashby,
who is very engaged in the science and policy debates on endocrine
disruption, said at a conference in March that he had decided
not to use parabens-containing products on his young daughter
(ENDS, 1999b).
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