What units of measure are used to report alcohol concentrations in blood and breath?
“Many methods of expressing blood alcohol concentration are in use throughout the world. One jurisdiction may express a concentration of 80 milligrams (mg) of alcohol in 100 mLs of blood as 80mg%. Since 80 mg is 0.08 grams, 0.08 grams of alcohol in 100 mLs may be written as 0.08%. In other words, 80 mg% is equal to 0.08% which is equal to 80 mg/dL (deciliter = 100 mLs). This value can also be described as 0.08 BAC. To confuse matters further, in some jurisdictions in the US they express the result in terms of breath (i.e. .080 grams per 210 liters of breath or .080 BrAC. In the UK where they assume a 2300:1 partition ratio, they express the same concentration as 34.78 ug/100mL.) As you can see this can be confusing. Check with the Regulating Agency to determine what unit of measure is used in the jurisdiction that you are concerned with.
