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Mouth alcohol
One of the most common causes of falsely high
breathalyzer readings is the existence of mouth alcohol.
In analyzing a subject's breath sample, the
breathalyzer's internal computer is making the
assumption that the alcohol in the breath sample came
from alveolar air—that is, air exhaled from deep within
the lungs. However, alcohol may have come from the
mouth, throat or stomach for a number of reasons. To
help guard against mouth-alcohol contamination,
certified breath test operators are trained to carefully
observe a test subject for at least 15-20 minutes before
administering the test.
The problem with mouth alcohol being analyzed by the
breathalyzer is that it was not absorbed through the
stomach and intestines and passed through the blood to
the lungs. In other words, the Breath Analyzer is
mistakenly multiplying the result. Consequently, a very
tiny amount of alcohol from the mouth, throat or stomach
can have a significant impact on the breath alcohol
reading.
Recent Drinking is the main cause of mouth Alcohol.
After consuming alcoholic drinks alcohol resides in the
mouth until it evaporates or is removed by eating food
and rinsing. This is the reason you are instructed to
wait at least 15 minutes since your last drink before
conducting a breath test, to avoid mouth alcohol. Also
mouthwash can give a subject a false alcohol reading.
Listerine contains 27% alcohol and without rinsing your
mouth of this can give false readings.
Other than recent drinking, a common source of mouth
alcohol is from belching or burping, or in medical terms
"eructation". This causes the liquids and/or gases from
the stomach—including any alcohol—to rise up into the
soft tissue of the esophagus and oral cavity, where it
will stay until it has dissipated.
Acid reflux, or gastroesophageal reflux disease, can
greatly exacerbate the mouth alcohol problem. The
stomach is normally separated from the throat by a
valve, but when this valve becomes herniated, there is
nothing to stop the liquid contents in the stomach from
rising and permeating the esophagus and mouth. The
contents—including any alcohol—are then later exhaled
into the breathalyzer.
Mouth alcohol can also be created in other ways.
Dentures, for example, will trap alcohol. Periodental
disease can also create pockets in the gums which will
contain the alcohol for longer periods. And recent use
of mouthwash or breath freshener—possibly to disguise
the smell of alcohol when being pulled over by
police—contain fairly high levels of alcohol.
Reference: WIKIPEDIA
Drink Driving
If you drive after drinking alcohol or taking other
drugs you are more likely to be involved in a crash.
Alcohol is absorbed quickly into the blood and travels
rapidly to all parts of the body. It affects your
brain’s ability to make judgments and process
information. It also impairs your consciousness and
vision too. Consuming alcohol prior to driving increases
one’s crash risk. Studies have shown that drivers are
twice as likely to crash with a BAC of 0.05g/100ml,
seven times as likely to crash with a BAC of
0.08g/100ml, while a BAC of 0.15g/100ml increases the
probability of a crash by 25 times 3.
Intoxicated drivers involved in fatal crashes are
three times more likely to have been speeding than sober
drivers 4. The initial introduction of RBT in
Western Australia in 1988 is reported to have had an
immediate impact on road crashes, decreasing the number
of fatal crashes by approximately 25%.
http://www.alcoholinfo.nsw.gov.au/injury_and_trauma/drink_driving?mysource_site_extension=printer_friendly_pages
How does alcohol affect your driving?
You don’t have to be drunk to be affected by alcohol. No
one drives as well as usual after drinking alcohol, even
though some people may look and act as though they are
unaffected. Alcohol is a depressant drug that affects
most areas of the brain.
Alcohol:
Slows brain functions so that you can’t respond to
situations, make decisions or react quickly.
Reduces your ability to judge how fast you are moving or
your distance from other cars, people or objects.
Gives you false confidence – you may take greater risks
because you think your driving is better than it really
is.
Makes it harder to do more than one thing at a time –
while you concentrate on steering, you could miss seeing
a red light, cars entering from side streets or
pedestrians.
Makes you feel sleepy or fatigued.
You cannot compensate for the effects of alcohol on your
brain.
Staying under the limit
Estimating your BAC is often inaccurate because:
The alcohol concentration of drinks vary from 2.5
percent (eg light beer) to over 40 percent (eg vodka,
whisky).
Beer may be served in pints, schooners or middies.
Wine glasses may vary in size from 100 to 280mls. Many
other drinks come in non-standard sizes.
Factors such as your gender, size, weight fitness,
health and liver function will all affect your BAC.
Also, the rate at which alcohol is eliminated from your
system varies from person to person.
So, don't try to estimate your BAC.
Measure it. The RTA recommends using an Australian
Standards approved (AS – 3547) breath testing device.
(See ADT’s BTA30DAS)
But remember:
Alcohol must not be consumed for at least 15 minutes
before testing because alcohol in your mouth will give
an artificially high reading.
Your BAC will rise for up to 2 hours after you stop
drinking.
If you go out drinking and have a big night you may
still be over the limit the next day so you may need to
take another test in the morning.
TM The Australian StandardsMark is a registered
trademark of SAI Global. For more information
visit
www.sai-global.com.au.
http://163.189.7.150/roadsafety/downloads/2005_04_drinkdrivingbrochure.pdf
http://druginfo.adf.org.au
Myths
A common myth is that breath testers can be "fooled"
(that is, made to generate estimates making one's blood
alcohol content appear lower) by using certain
substances. An episode of the Discovery Channel's
MythBusters tested substances usually recommended in
this practice—including breath mints, mouthwash, and
onion—and found them to be ineffective. Adding an odor
to mask the smell of alcohol might fool a person, but
does not change the actual alcohol concentration in the
body or on the breath.
Products such as mouthwash or breath spray can "fool"
breath machines by significantly raising test results.
Listerine, for example, contains 27% alcohol; because
the breath analyzer will assume the alcohol is coming
from alcohol in the blood diffusing into the lung rather
than directly from the mouth, it will apply a "partition
ratio" of 2100:1 in computing blood alcohol
concentration—resulting in a false high test reading.
Factors affecting your BAC
The more you drink, the higher your BAC. But two people
who drink the same amount might register quite different
BACs. There are many factors that will affect this,
including:
Body size:
A smaller person will have a higher BAC than a larger
person because the alcohol is concentrated in a smaller
body mass.
Empty stomach:
Someone with an empty stomach will reach a higher BAC
sooner than someone who has just eaten a meal. Food in
the stomach slows down the rate at which alcohol passes
into the bloodstream.
Body fat:
People with a lot of body fat tend to have higher BACs
because alcohol is not absorbed into fatty tissue, so
alcohol is concentrated in a smaller body mass.
Women:
After drinking the same amount of alcohol, a woman will
almost always have a higher BAC than a male.
Because of all these variable factors, counting the
number of standard drinks you consume can only give a
rough guide to your BAC. For more detailed information
about alcohol and how it effects you, please see the
Australian Drug Foundation website.
It is safest not to drink alcohol at all if you are
going to drive. The more alcohol you have in your body,
the more risk you have of crashing.
Facts:
· At 0.05% Blood Alcohol Content (BAC), your risk of
being involved in a road crash is double that of a 0.00%
reading.
· At 0.1% BAC your risk is more than seven times as high
of being involved in a road crash, than at 0.00%.
· At 0.15% your risk increases to 25 times that of
driving at 0.00%.
AUSTRALIAN FEDERAL POLICE
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