Breath alcohol screening test

Potassium dichromate oxidation of ethanol to acetic acid is the basis for the original breath alcohol screening test used by law enforcement agencies to determine a person s blood alcohol content. The test is based on the difference in color between the dichromate ion (reddish orange) in the reagent and the chromium(lll) ion (green) in the product. Thus, color change can be used as a measure of the quantity of ethanol present in a breath sample ... 

In its simplest form, a breath alcohol screening test consists of a sealed glass tube containing a potassium dichromate-sulfuric acid reagent impregnated on silica gel. To administer the test, the ends of the tube are broken off, a mouthpiece is fitted to one end, and the other end is inserted into the neck of a plastic bag. The person being tested then blows into the mouthpiece until the plastic bag is inflated. 

Only evidential breath testing devices (EBTs) and alcohol screening devices (ASDs) on the National Highway Transportation Safety Administration (NHTSA) conforming products list (CPL) may be used for alcohol screening tests. An ASD that is on the NHTSA CPL for DOT alcohol tests may only be used if there are instructions for its use in Part 40. 

An STT can conduct only alcohol screening tests. Alcohol confirmation tests must be performed by a breath alcohol technician (BAT). 

Alcohol screening test A procediire to determine whether a driver may have a prohibited concentration of alcohol in a breath or saliva sample. 

Although methanol and isopropyl alcohol are much more toxic than ethanol and would rarely be found in one s breath, would these two compounds also give a positive alcohol screening test If so, what would be the products of these reactions ... 

For collectors, breath alcohol technicians (DATs) or screening test technicians (STTs), a pattern or practice of using forms, testing equipment, or collection kits that do not meet Part 40 standards ... 

Key DOT alcohol testing requirements, including the testing process, the role of breath alcohol technicians (BATs), screening test technicians (STTs), and problems in alcohol tests ... 

Alcohol confirmation test A second alcohol test using an evidential breath testing device (EBT), following a screening test with a result of 0.02 or greater that provides quantitative data about the alcohol concentration. 

Alcohol screening device (ASD) A breath or saliva device (other than an evidential breath testing device (EBT)) that is approved by the National Highway Traffic Safety Administration (NHTSA) and placed on a conforming products list for such devices. 

Screening Test Technicians and Breath Alcohol Technicians need no written authorizations from employees to perform DOT saliva or breath alcohol tests (as appropriate), or to report alcohol test results to employers. 

The screening test is the initial alcohol test. A confirmation test is only performed if the screening test shows an alcohol concentration of 0.02 or higher. Note that only breath or saliva can be tested, not urine, blood, or any other substance. 

The oxide-semiconductor-based ethanol sensor is being used to screen intoxicated drivers. In the test condition on the road, the ambient concentrations of CO and N02 can be up to 100 and lOppm due to the emissions from gasoline and diesel engines, respectively.61 The results shown in Fig. 12.6 suggest that the present sensors may be applied for selective detection of ethanol. Acetone is a very rare component in an ordinary ambient atmosphere. However, the expiration of a diabetes patient can contain acetone.62 Acetone concentration in breath air can reach up to 300 ppm in the case of an aceto-acidotic coma related to diabetes mellitus.63,64 This might interfere the ethanol sensor. A high selectivity to ethanol is required for such applications. The SZ sensor at 300°C and the ZW sensor at 400°C can satisfy these requirements. On the contrary, to examine the health condition of a diabetes patient, selective detection of acetone without the interference with alcohol is desirable. In this case, the W sensor at 400°C will be of advantageous. 

When testing for alcohol, most employers use a breath testing device. The results tell if the individual is under the influence of alcohol at the time the breath sample is taken. Saliva testing is sometimes used to screen for alcohol, but confirmation by breath testing is preferred. 

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