Many bacteria do not deserve a death sentence and if you
intend to kill them all, you may have to pay a price.
A new study found that an antibacterial known
as triclosan widely used in a range of household products to help sterilize
hands could do more harm than good.
The study published in ES&T’s Research ASAP website
(DOI: 10.1021/es062227l) by Peter Vikesland and colleagues at the Virginia Polytechnic
Institute and State University found that under normal conditions, use of
products containing triclosan could trigger production of a probable carcinogen
chloroform in an amount 40 percent higher than the background level in tap
water treated with chlorine.
In 2005, Vikesland and colleagues released results of a
study in the Environmental Science and Technology, causing quite some stir in
the industry, which showed that in laboratory settings, pure triclosan can react
with free chlorine and generate toxic chloroform.
The findings reported by
London's Evening Standard newspaper have prompted
the British chain Marks & Spencer to remove all triclosan containing
products from store shelves. Ensuing news reports also triggered withdrawal of
triclosan containing tooth paste in Chinese stores.
At that time, Vikesland warned that the findings were preliminary
and the added triclosan in household products may not act as in the same way as
its pure counterpart does to cause formation of toxic chloroform.
But his new study of real products with real
triclosan present proved that caution needs to be excised when using with
triclosan containing products.
In his new study, Vikesland and his colleagues tested a
total of 16 products including lotions, soaps and body washes with and without
The discovery was shocking:
all products with triclosan produced either chloroform or other chlorinated
They estimated the users of
the triclosan containing products would expose themselves to chloroform at a
level 40% higher than the amount found in tap water.
Triclosan in some soap can degrade quickly. It can decompose
within 1 minute when exposed to chlorinated water at 40 o C, which
is commonly used at a household environment.
The amount of chloroform formed by triclosan depends on the location of
tap water with little formed in
and moderate levels formed in
VA water, according to the EST
The decomposition speed is so fast that the researchers
doubt that triclosan can provide any germ-killing benefits.
“At fairly low levels of chlorine, the
triclosan degrades rapidly,” Vikesland is quoted as saying by the EST news.
The researchers say it remains unknown how the chloroform
formed by triclosan would impact each individual who uses triclosan containing
More research is needed to
assess the potential risk.
A scientist with foodconsumer.org suggests that consumers
should be aware that not all bacteria need to be killed.
When you try hard to eliminate all bacteria
with all toxic chemicals, you may have a good chance to get injured in a long
run. Clean water with ordinary soap just work as well as its counterparts with triclosan.