What is LawBrain?
It's a living legal community making laws accessible and interactive. Click Here to get Started »

Difference between revisions of "Breathalyzer test"

From lawbrain.com

(See Also)
(3 intermediate revisions by 2 users not shown)

Latest revision as of 22:00, 28 May 2014

A breathalyzer test is a form of field sobriety test which determines if your blood alcohol content exceeds the legal limit.

  • This LawBrain entry is a stub. Please help us expand it! Click the 'Edit' tab above to add to this page.



Alcohol (C2H5OH) is a drug that affects the nervous system and, even in small amounts, can impair an individual's judgment and ability to drive.[1]  Approximately, one-third of car accidents are related to alcohol. The breathalyzer test was created in 1954 and continues to be most commonly used to measure someone's blood alcohol content ("BAC").[2]

Each jurisdiction sets a different legal limit for BAC depending usually on the physical attributes of the driver (i.e. weight, age, height). Generally, it is illegal to operate a motor vehicle with a BAC of 0.08 percent or higher. The legal limit for BAC is a means of measuring the degree of the driver's impairment due to alcohol.[3]

The breath-test machine is designed to measure the amount of alcohol in a deep-lung breath sample and to use that amount to determine BAC. The four main scientific methods used in the various machines are chemical analysis, infrared spectrophotometry, gas chromatography and fuel-cell detection. [4]

A breathalyzer test measures someone's level of alcohol by using a chemical reaction. The kit includes several vials of distinct chemicals that change color when exposed to alcohol, with each color change representing a different concentration of alcohol.[5]

While a blood test is arguably more reliable, the breath test for BAC is more commonly used in the field because the testing equipment is convenient to transport and because the test is easier to administer, can be used by non-medical personnel, is less physically intrusive to the person taking the test and produces results faster. However, under certain circumstances, breath tests can be less than reliable as an accurate measure of BAC.[6]

Legal Issues

Reliability of Breath-Test Results

Reach indicates that breath tests results can exaggerate an individual's actual blood alcohol concentration by at least 15%. Possibly 23% of all individuals test will receive an exaggerated BAC reading.[7]

Many breathalyzers do not just identify the ethanol present in alcoholic beverages, but also some other compounds and substances with similar molecular structure. The breath of an average human contains over one hundred compounds and around 70 to 80 percent of them contain similar molecular structure as that of ethanol.[8] Additionally, improper calibration/use, poor training, and normal wear and tear can impact the accuracy of any device.[9]

The National Safety Council Committee on Alcohol and Other Drugs has recommended that at least two separate breath samples be collected and analyzed individually. Conducting two separate analyses is critical in performing any quantitative evidential breath alcohol analysis. The breath samples should be collected at intervals of not less than 2 nor more than 10 minutes, after an initial deprivation period of at least 15 minutes.[10]

Implied Consent Laws

Each jurisdiction has enacted implied-consent laws which states that every licensed driver within the jurisdiction gives their consent to chemical testing in order to determine their BAC whenever asked by a law enforcement officer. Most jurisdictions will suspend or revoke your drivers license if you refuse to submit to a breathalyzer test. [11] Some jurisdictions permit a driver to refuse the breathalyzer test until an independent third party arrives to administer it. [12]

Officers are not allowed to ask for a breath test arbitrarily - generally they must have reasonable suspicion that criminal activity is afoot. Signs of visible intoxication must be apparent for the officer to request a breath test. [13]


  1. http://www.bxscience.edu/publications/forensics/articles/toxicology/r-toxi01.htm
  2. http://www.criminal-law-lawyer-source.com/terms/breathalyzer-sobriety-test.html
  3. http://www.bloodalcoholcontent.org/
  4. http://www.1800dialdui.com/CM/FSDP/PracticeCenter/Criminal-Law/Drunk-DrivingDUI.asp?focus=topic&id=3
  5. http://www.criminal-law-lawyer-source.com/terms/breathalyzer-sobriety-test.html
  6. http://www.1800dialdui.com/CM/FSDP/PracticeCenter/Criminal-Law/Drunk-DrivingDUI.asp?focus=topic&id=3
  7. http://www2.potsdam.edu/hansondj/DrivingIssues/1093825780.html
  8. http://www.articlesbase.com/health-articles/myths-and-facts-about-using-breathalyzers-864604.html
  9. http://www.illinoisduiattorney.com/breathalyzer-testing
  10. http://www.duicentral.com/evidence/breathalyzer_accuracy_2.html
  11. http://www.1800dialdui.com/CM/FSDP/PracticeCenter/Criminal-Law/Drunk-DrivingDUI.asp?focus=topic&id=3
  12. http://www.ehow.com/list_6678526_breathalizer-laws.html
  13. http://www.legalinfo.com/content/dui-dwi/what-is-implied-consent.html

External Links

Related Resources on FindLaw

Related Blogs on FindLaw

Failed to load RSS feed from http://search.yahooapis.com/WebSearchService/rss/webSearch.xml?appid=yahoosearchwebrss&query=breathalyzer%20site:blogs.findlaw.com!

                                                                            Web Services by Yahoo!

See Also


FindLaw Nira, FindLaw Pierre, FindLaw Sarah, Sfitzpatrick