Concentration units used to report blood- and breath-alcohol concentration for legal purposes differ between countries which is important to consider when blood/breath ratios of alcohol are compared and contrasted.

Publisher: Blackwell Pub Country of Publication: United States NLM ID: 0375370 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1556-4029 (Electronic) Linking ISSN: 00221198 NLM ISO Abbreviation: J Forensic Sci Subsets: MEDLINE

Publication: 2006- : Malden, MA : Blackwell Pub.
Original Publication: [Chicago, Ill.] : Callaghan and Co., 1956-

Blood Alcohol Content* ; Breath Tests* ; Ethanol*/analysis ; Ethanol*/blood ; Driving Under the Influence*/legislation & jurisprudence ; Central Nervous System Depressants*/analysis; Humans ; Forensic Toxicology

This technical note reviews the plethora of concentration units used to report blood-alcohol concentration (BAC) and breath-alcohol concentrations (BrAC) for legal purposes in different countries. The choice of units sometimes causes confusion when scientific papers originating from a certain country might be introduced into evidence via expert testimony, such as when alcohol-related crimes are prosecuted. The concentration units are also important to consider when blood/breath ratios (BBRs) of alcohol are calculated and compared between countries. Statutory BAC limits for driving in most nations are reported in mass/volume (m/v) units, such as g/100 mL (g%) in the United States, mg/100 mL (mg%) in the United Kingdom and Republic of Ireland, or g/L (mg/mL) in many EU nations. By contrast, Germany and the Nordic countries report BAC as mass/mass (m/m) units, hence g/kg or mg/g, which are ~5.5% lower than m/v units, because whole blood has an average density of 1.055 g/mL. There are historical reasons for reporting BAC in mass/mass units because the aliquots of blood analyzed were measured by weight rather than volume. The difference between m/m and m/v is also important in postmortem toxicology, such as when distribution ratios of ethanol between blood and other biological specimens, such as urine, vitreous humor, and cerebrospinal fluid, are reported.
(© 2024 American Academy of Forensic Sciences.)

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Keywords: alcohol; analysis; blood; breath; concentration units; drunken driving; ethanol; jurisprudence

0 (Blood Alcohol Content)
3K9958V90M (Ethanol)
0 (Central Nervous System Depressants)

Date Created: 20240323 Date Completed: 20240626 Latest Revision: 20240626

20240627

10.1111/1556-4029.15511

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