ABSTRACT
The National Transportation Safety Board recommended lowering the legal blood-alcohol limit to 0.05 g/dL for motor vehicle operators in the United States. In 1995 the US Department of Transportation established a mandatory per se blood-alcohol testing limit of 0.04 for commercial drivers and other individuals in safety-related positions. Alcohol impairment begins at very low alcohol concentrations and rapidly increases as a function of alcohol concentration. Laboratory experiments with low concentration of blood alcohol clearly demonstrate that impairment begins at 0.015 and increases with rising alcohol concentration. Alcohol concentrations reported by breath-alcohol instruments in the United States typically are lower than those found in the blood. Breath- and blood-alcohol concentrations involving patients with pulmonary dysfunctions were studied to determine what, if any, difference could be found with healthy individuals. The ultimate goal of a per se alcohol limit is public safety and the reduction of deaths and injuries known to be associated with increasing alcohol concentrations.
