Triclosan and Antibiotics resistance
Context - Triclosan is added to many consumer goods such as cosmetics and detergents to kill microorganisms or inhibit their growth. It serves as disinfectant, preservative or antiseptic and is widely used in health care and animal husbandry.
There is concern that this widespread use of triclosan may lead to the emergence or proliferation of harmful bacteria that are resistant to both biocides and antibiotics.
In the light of current scientific evidence, can triclosan lead to antibiotic resistant bacteria?
2. What are the main uses of triclosan?
Triclosan is used in detergents and soaps
Credit: Sanja Gjenero
Triclosan is widely used,
notably in personal care products such as cosmetics, but also in
textiles and in plastics.
triclosan serves as a
preservative. It is also
included in soaps, in deodorants and in toothpastes – to control plaque
and improve the health of the gums.
In health facilities,
triclosan helps prevent and
control infections. It is contained in hand washes,
disinfectants and is also
integrated into surfaces of medical devices such as surgical suture
Triclosan is added to many
household products such as soaps and
detergents. It is also
included into some articles such as children’s toys, carpets and
textiles to prevent microorganisms
from growing on them.
In the EU, triclosan may neither
be used in food, nor in food contact material, nor in animal feed. But
it may be used in biocidal products
for veterinary hygiene.
3. What happens to triclosan in the environment?
Because of it widespread use
triclosan finds its way into
wastewater. In treatment plants most triclosan is removed and the
remainder is discharged into surface
waters. The removed triclosan is partly broken down, but
about half of it ends up in treatment sludge and may enter the
environment if the sludge is used to fertilize agricultural
Although, triclosan is
chemically very stable, it can be broken down by light, ozone,
chlorine, and some
If present in soil, triclosan
does not seem to affect bacterial
activity, but it may disrupt the nitrogen
5. Can bacteria become resistant to Triclosan?
Bacteria that grow as a biofilm are able to survive hostile
Credit: Janice Carr
Some bacteria are naturally
unaffected by triclosan. Others
have developed mechanisms of defence against it when exposed to low
concentrations of triclosan
in the laboratory. When such mechanisms involve changes at
genetic level they could be
passed to the next generations or even between different bacteria.
triclosan sometimes work
in similar ways. Some laboratory studies have shown that when exposed to
triclosan, bacteria can develop
resistance that can make them
resistant to other
antimicrobials or, worse,
to antibiotics. Such cross-resistance if occurring in real situations
could have severe consequences for public health.
There is very little research on
bacterial exposure to
triclosan in the
environment and its impact but so far, there is no evidence that the
widespread use of triclosan has caused
Standard protocols for the evaluation of
bacterial resistance to
biocides need to be
developed. It would also be useful to identify
genetic characteristics that
enable bacteria to develop
6. Conclusions of the SCCS
Resistant bacteria can survive biocide concentrations that would
There are several reasons why the use and release of
triclosan into the
environment could pose a risk:
Triclosan is the most studied
biocide with respect to
resistance, especially its action
on bacteria and mechanisms of
microbial resistance. However, laboratory conditions may differ from
real life conditions and information is still insufficient about the
amount and impact of triclosan on bacteria in the environment.
The Scientific Committee on Consumer Safety (SCCS) concludes that to
date, there is no evidence that using
triclosan leads to an increase
resistance. However it is too
early to say that triclosan exposure never leads to microbial
resistance, as there is not yet enough information to make a full risk
To preserve the role of
infection control and hygiene,
SCCS can only recommend its prudent use, for instance limited to
applications where a health benefit can be demonstrated.