Hand Sanitizers Don't Kill Anywhere
Near The Claims Made By Manufacturers
Using hand sanitizer won't necessarily kill 99.99 per cent of
germs on your hands despite the claims made by many such products,
a CBC investigation has found.
CBC News tested three popular sanitizers top-selling Purell,
President's Choice and Soapopular on a class of Grade 8
students at Ryerson Middle School in Hamilton, Ont., last month.
President's Choice and Purell both contain alcohol, while Soapopular
contains no alcohol but rather an immune
suppressing and carcinogenic agent called benzalkonium chloride.
Students were divided into three groups of six and a different
hand sanitizer was assigned to each one.
The CBC enlisted the help of microbiologist Jason Tetro of the
Ottawa-based Centre for Research on Environmental Microbiology.
Students were divided into three groups of six and a different
hand sanitizer was assigned to each one.
The CBC enlisted the help of microbiologist Jason Tetro of the
Ottawa-based Centre for Research on Environmental Microbiology.
The students weren't asked to wash their hands before the test.
They began the test with their fingers contaminated by whatever
they had touched on a lunch break.
Tetro took swabs of their hands to get a baseline measure of
the bugs and germs lurking around fingernails and in creases.
Students then liberally rubbed their hands with sanitizer. A
second swab was taken and the results were sent to Tetro's lab.
He helped explain them once they came back.
And they needed a little explaining.
Test results
President's Choice killed an average of 54.6 per cent of microbes
on the kids' hands. Purell killed about 60.4 per cent. And Soapopular
killed 46 per cent.
So why did CBC's results differ so much from the claims on hand-sanitizer
bottles and websites?
According to Tetro, the companies are not deliberately misleading
consumers. They've had to test their products in accredited labs
before Health Canada would allow them to make the 99.99 per cent
claim.
Tetro knows this because he's carried out hundreds of similar
tests.
"The claim is based on these very controlled laboratory
tests and we do those tests here at the lab," he said.
When hand sanitizers undergo testing, the hands they're tested
on are first sanitized in the lab, then sprinkled with microbes
in a controlled situation.
"We wash the hands. We make sure they are clean and devoid
of any germs, then we artificially put the germs on their finger
pads. Then we test to find out whether the product kills or eliminates
it," said Tetro.
Grease and grime protect germs
Hand sanitizers don't work as well on really dirty hands because
grime and grease actually protect germs from being destroyed.
"In a real life situation, we don't know how clean those
hands are and so you're not going to see anywhere near the type
of results [identified on the bottle]," Tetro said.
All three firms were critical of CBC's test results.
"We feel the methodology used by CBC is unscientific and
therefore the result is not representative of President's Choice
hand sanitizer's true potential," wrote David Primorac, senior
director of public relations for Loblaw Companies Ltd., which
sells President's Choice products.
"We clearly believe the 54 per cent results achieved by
the CBC are inaccurate and misleading," wrote Primorac, who
also questioned whether the students were tested in exactly the
same method under controlled conditions.
"I ask these questions because we get these inquiries now
and again and it is extremely important that this is an apples-to-apples
comparison. The slightest deviation can skew results," Primorac
wrote.
Test conditions not 'real world': Loblaw
He said Loblaw has tested its sanitizer in "real world"
conditions in a Health Canada accredited lab.
"We brought in volunteers from real life situations and
measured the microbial load on their hands before use and after
use. Seventy-nine per cent of the subjects achieved 100 per cent
kill rate with 21 per cent achieving 99 per cent or over kill
rate," Primorac wrote.
Purell said it was "unable to comment on the accuracy of
any third-party data we haven't reviewed" and that it was
"confident in the science that supports our claims and the
efficacy of Purell hand sanitizer."
Soapopular said in a statement that CBC's results were "less
than half of any result reported during literally hundreds of
previous tests conducted for health and safety agencies in all
G8 countries and ministries of health in over 65 countries."
The companies acknowledged that sanitizers are an alternative
when soap and water aren't available, but they are not meant to
substitute for hand washing.
So it all comes back to the advice that doctors and mothers give
all the time: Wash your hands with soap and water.
Immune Suppressing, Carcinogenic
Hand Sanitizers in Schools to Prevent H1N1 Flu
Reference Sources: cbc.ca
December 3, 2009
...............................................................................................................
|