<p>Blood Alcohol Concentration (BAC) is the percentage of alcohol in the blood. It is equivalent to <a href="https://drugtestingace.com/resources/glossary/define-saliva-alcohol-concentration-sac">Saliva Alcohol Concentration (SAC)</a>. DOT federally-mandated zero tolerance levels of 0.02% &#8211; 0.30% indicates impairment.</p>