Breathalizer tests can convict people wrongly eg dieters and diabetics or those who've eaten certain bread products

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Breathalizer tests faulty>must know info before you drink

 

A friend of mine (a lawyer) showed us an experiment with the breathalizer

tester that police use to confict people of over drinking.

He showed that after just one drink a simple blow into the tube brings up

the results equivalent to over the limit consumption.

What he recently proved in court (and won) was that after washing the mouth

out with good ole H2O (water) the test results were normal!!!

I then asked:

" How many people are getting screwed by the simple fact that they should

rinse there mouth out before taking the test? "

He shrugged and shook his head.

They (police) know this and yet they don´t even try to assist the one´s they

are testing in getting a fair reading. So remember this for yourselves

folks!

The person my friend was defending just had ONE drink but the test said he

was over the limit. One drink shows up way past the legal limit. Rinse your

mouths out before submitting to the test.

I am not one to consume alcohol. Personal preverance. But I do not like the

fact that people are being unfairly tested so I put this information out for

who ever wants to tuck this bit of information under there belt.

Drink responsibly and RINSE your mouth out!

 

 

Anonymous Coward

8/6/2004

7:56 pm EDT Breathalizer tests faulty>must know info before you drink

 

The test picks up the alcohol that is dispelled from your lungs as the blood

discharges unwanted gases.

 

 

 

 

 

 

 

http://www.duicenter.com/books/dd_book/chemical.html

 

One of the major defects in many methods of blood-alcohol analysis is the

failure to identify ethanol (also referred to as ethyl alcohol) to the

exclusion of all other chemical compounds. To use the terminology of

scientists, such methods are not specific for ethanol: They will detect

other compounds as well, identifying any of them as " ethanol. " Thus a client

with other compounds in his blood or breath may have a high " blood-alcohol "

reading with little or no ethanol in his body.

 

This problem of nonspecificity is most noticeable in the use of infrared

breath analyzing instruments, such as the various Intoxilyzer models, the

Intoximeter 3000 and the BAC Datamaster. CMI´s so-called " state-of-the-art "

Intoxilyzer Model 5000 (and its various permutations), the most widely used

breath machine in service today, utilizes infrared spectroscopy. Yet

infrared analysis is particularly susceptible to giving false readings due

to nonspecificity. In fact, the single greatest flaw in the Intoxilyzer

itself--and the most productive area for cross-examination--is the machine´s

inherent lack of specificity. The technical reason for this lack of

specificity is that the Intoxilyzer is not designed to detect the molecule

of ethyl alcohol (ethanol), but rather only a part of that molecule--the

methyl group. In other words, it is the methyl group in the ethyl alcohol

compound that is absorbing the infrared light, resulting in the eventual

blood-alcohol reading. Thus the machine will " detect " any chemical compound

and identify it as ethyl alcohol if it contains a methyl group compound

within its molecular structure. The Intoxilyzer assumes that the methyl

group is a part of an ethyl alcohol compound.

 

The simple fact is that there are numerous compounds that contain the methyl

group. Among these are isopropyl alcohol, propane, butane, propylene,

methane, ethane, ethyl chloride, acetic acid, butadiene, dimethylether,

dimethylamine and dimethylhydrazine. Acetone and acetaldehyde both contain

the methyl group in their structure--and, interestingly, each can be found

on the human breath. In fact, recent studies have found that over one

hundred chemical compounds can be found on the breath at any given moment in

time (see Table 1). More important, approximately 70 to 80 percent of these

compounds contain methyl groups. And the infrared breath machine will detect

each of these as " ethyl alcohol. "

 

To make matters worse, the machine detects alcohol through " additive

absorption. " In other words, the more methyl groups the instrument detects

by their absorbing the infrared energy, the higher will be the blood-alcohol

reading. Thus all of the non-alcoholic compounds on the breath will have a

cumulative effect--that is, the errors will be added one on top of another.

 

To approach this problem of specificity from another angle, ethanol has a

peak absorption at approximately 3.39 microns, with the band of absorption

declining rapidly on each side. However, ethanol has wide absorption bands

and peaks at other wavelengths as well, such as bands in the 7.25, 9.5 and

11.0 micron range. Yet the Intoxilyzer screens out these wavelengths and

attempts to identify the substance, ethanol, on the basis of only one, two,

or three bands, depending on the model. This reduces the efficiency of the

Intoxilyzer, since other elements besides ethanol absorb in these ranges,

but few, if any, of them would also absorb in the 7.25, 9.5 and 11.0 micron

ranges.

 

To make this point conceptually simpler, the analogy of fingerprint

identification has been used. Ethanol has a " fingerprint " in that it will

absorb energy wavelengths of roughly 3.39, 7.25, 9.5 and 11.0 microns. While

many other substances have fingerprints that will include the 3.39 range or

the 7.25 range or the 11.0 range, probably none of them will have all of

them--that is, the full print of ethanol. By fingerprint analogy, then,

absorption of light wavelengths at about 3.39 microns represents a single

" point of identity " ; absorption at several bands would represent more points

of identity.

 

Certainly, fingerprint identification is considered more positive because

there are many points of identity and, conversely, availability of only one,

two, or three points of identity in fingerprinting would preclude an

expert´s opinion as to similarity. Yet the Intoxilyzer attempts to identify

a substance on the basis of one, two, or three points of identity, despite

the availability of other points that would exclude all substances other

than ethyl alcohol.

Anonymous Coward

8/6/2004

8:13 pm EDT Breathalizer tests faulty>must know info before you drink

 

http://www2.potsdam.edu/alcohol-info/DrivingIssues/1055505643.html

 

 

....A major problem with some machines is that they not only identify the

ethyl alcohol (or ethanol) found in alcohol beverages, but also other

substances similar in molecular structure. Those machines identify any

compound containing the methyl group structure. Over one hundred compounds

can be found in the human breath at any one time and 70 to 80 percent of

them contain methyl group structure and will be incorrectly detected as

ethyl alcohol. Important is the fact that the more different ethyl group

substances the machine detects, the higher will be the false BAC estimate.

 

The National Highway Traffic Safety Administration (NHTSA) has found that

dieters and diabetics can have acetone levels hundreds and even thousand of

times higher than that in others. Acetone is one of the many substances that

can be falsely identified as ethyl alcohol by some breath machines.

 

One investigator has reported that alcohol-free subjects can generate BAC

readings of about .05 after eating various types of bread products.

 

Substances in the environment can also lead to false BAC readings. For

example, an alcohol-free subject was asked to apply a pint of contact cement

to a piece of plywood and then to apply a gallon of oil-base paint to a

wall. The total activity lasted about an hour. Twenty minutes later the

subject was tested on an Intoxilyzer, which registered a BAC of .12 percent.

This level is 50% higher than a BAC of .08, which constitutes legal

intoxication in many states.

 

 

Ignition Interlocks

 

An ignition interlock is a device installed in a vehicle to prevent its use

if a driver has been drinking alcohol. It includes a breath testing device

into which the driver must blow before starting the engine.

 

The blood-alcohol concentration (BAC) limit for starting the car is very

low, under .025, which is less than 1/3 the legal limit of .08. Therefore

drivers are advised by authorities not to eat or smoke before trying to

start their vehicles. Otherwise, the device may prevent them from driving.

 

Source: Repeat DUI offenders to get ignition interlock: blood-alcohol level

must be below .025 to start car. TheWGALChannel.com, 10-1-03.

 

 

Similarly, a painter with a protective mask spray painted a room for 20

minutes. Although a blood test showed no alcohol, an Intoxilyzer falsely

reported his BAC as .075.

 

Any number of other products found in the environment can cause erroneous

BAC results. These include compounds found in lacquers, paint removers,

celluloid, gasoline, and cleaning fluids.

 

Other common things that can cause false BAC levels are alcohol, blood or

vomit in the subject´s mouth, electrical interference from cell phones and

police radios, tobacco smoke, dirt, and moisture.

 

Breath testers can be very sensitive to temperature and will give false

reasings if not adjusted or recalibrated to account for ambient or

surrounding air temperatures. The temperature of the subject is also very

important. Each one degree of body temperature above normal will cause a

substantial elevation (about 8%) in apparent BAC.

 

Many breath testing machines asume a 2,100-to-1 ratio in converting alcohol

in the breath to estimates of alcohol in the blood. However, this ratio

varies from 1,900 to 2,400 among people and also within a person over time.

This variation will lead to false BAC readings.

 

Physical activity and hyperventilation can lower apparent BAC levels. One

study found that the BAC readings of subjects decreased 11 to 14% after

running up one flight of stairs and 22-25% after doing so twice. Another

study found a 15% decrease in BAC readings after vigorous exercise or

hyperventilaion.

 

Some breath analysis machinnes assume a hematocrit (cell volume of blood) of

47%. However, hematocrit values range from 42 to 52% in men and from 37 to

47% in women. A person with a lower hematocrit will have a falsely high BAC

reading.

 

Failure of law enforcement officers to use the devices properly or of

administrators to have the machines properly maintained and re-calibrated as

required are additional sources of error.

 

Research indicates that breath tests vary at least 15% from actual blood

alcohol concentration. At least 23% (that´s about one out of every four) of

all individuals tested will have a BAC reading higher than their actual BAC.

 

One writer has observed that:

 

" Breath testing, as currently used, is a very inaccurate method for

measuring BAC. Even if the breath testing instrument is working perfectly,

physiological variables prevent early reasonable accuracy....Breath testing

for alcohol using a single test instrument, should not be used for

scientific, medical or legal purposes where accuracy is important. "