BAL; a legal measurement of alcohol concentration in the bloodstream, determining whether a person is considered legall;impaired or intoxicated. The blood alcohol level is usually stated as a percentage, such as 0.10%. In most U.S. states,this is a measurement of weight by volume (w/v). In a few states, the measurement is the percentage mass concentratior(w/w, or mg of alcohol per mg of blood). Internationally, blood alcohol levels are often stated in millimoles per liter (rnrnol/L^1 millimole per liter is equal to 4.61 mg/dL or 0.00461% w/v. In the other direction, each 0.01% w/v is equal to about 2.169mmol/L