Lot's Wife Edition 5 2015

SCIENCE & ENGINEERING 35
Hand Sanitiser:
Friend or Foe?
Since its introduction to the public in the 1990s, hand sanitiser
has rapidly grown in popularity. Although its original use was to
minimise the spread of bacteria in hospitals, it has now become
quite common for people to use it on a day-to-day basis.
As we become more and more aware of the harmful bacteria
present in our environment (especially in public places) it is
quite understandable that many of us have become somewhat
‘germaphobic’. It makes sense then that we fight the germs (and
ease our hypochondria) with a little hand sanitiser now and then.
But could hand sanitiser be doing us more harm than good?
Since its introduction to the public in the 1990s, hand
sanitiser has rapidly grown in popularity. Although its
original use was to minimise the spread of bacteria in
hospitals, it has now become quite common for people to
use it on a day-to-day basis. As we become more and more
aware of the harmful bacteria present in our environment
(especially in public places) it is quite understandable
that many of us have become somewhat ‘germaphobic’. It
makes sense then that we fight the germs (and ease our
hypochondria) with a little hand sanitiser now and then. But
could hand sanitiser be doing us more harm than good?
As many of us have already heard, there is talk of ‘super
bugs’ arising from our overuse of antibacterial substances.
For those who haven’t – hand sanitiser (as well as other
antibacterial cleansers) kills up to 99.9% of bacteria. This
means that the surviving .1% of that bacterial population is
immune to the antibacterial agent used. This strain then
reproduces, creating a whole new population of bacteria
much stronger than the last. Re-exposure to antibacterial
cleansers then kills the weaker members of this new strain
meaning the survivors are even stronger and less responsive
to antibiotics. Repeat the cycle again and soon enough, we’ll
be left with super bugs – scary! Unfortunately, in addition
to killing harmful bacteria, antibacterial soaps and hand
sanitisers also kill off our bodies’ good bacteria, making it
even easier for antibiotic-resistant strains to flourish. But
this isn’t even the worst part.
A peer-reviewed journal published in october last year
has shown that using hand sanitiser before exposure to
bisphenol A (BPA) can increase its absorption into our bodies.
BPA is an industrial chemical commonly found in plastics,
including food and beverage packaging. BPA has been linked
to heart disease, hormone disorders, cancer and infertility,
but the Food and Drug Administration has deemed it safe
in low concentrations. Although most of our BPA exposure
comes from food and beverage packaging, thermal receipt
paper is coated with BPA and therefore contains high
quantities of it. The study found that hand sanitiser (as well
as other skin care products) contains mixtures of dermal
penetration enhancing chemicals – in other words, chemicals
that make our skin more absorbent. These are primarily
used to increase the transdermal delivery of drugs. However,
these chemicals have been found to also increase the dermal
absorption of lipophilic compounds such as BPA by up to 100
fold! To make matters worse, people who touched the receipt
paper immediately after using hand sanitiser transferred
significant amounts of free BPA to food they subsequently
touched, thus doubling their exposure. This combination of
dermal and oral absorption resulted in "rapid and dramatic
average maximum increase in bioactive BPA" which – simply
put – means an increased risk of an array of diseases.
Dermal penetration enhancers include the chemicals
triclosan, isopropyl myristate and propylene glycol. These are
commonly found in popular hand sanitiser brands such as
Dettol and Purell. However, on their own these tend to be fairly
safe – with the exception of triclosan. Studies have linked
triclosan to disrupted hormonal development, a reduction
in bacterial resistance and an increase in allergies. The
European Union has already banned the use of triclosan in
all products and the US has reviewed its use with talks of a
potential ban. So look out for this one on the ingredients list.
Luckily, it’s not all doom and gloom. According to the CDC
(Centres for Disease Control and Prevention) washing your
hands the old-fashioned way (with soap and water) for just
20 seconds can be just as effective at ridding your hands
of the nasties without the side effects. In fact, regular hand
soap has been found to be much more effective at ridding
your hands of fat and sugar deposits than hand sanitisers.
Germs aren’t all bad, and are actually a major part of
an active and efficient immune system. Just remember to
wash your hands with some soap and water before eating or
rubbing your eyes and your body will thank you for it.
Image Courtesy of: www.flickr.com/photos/subsetsum/