Blood Alcohol Content is the legal name for BAC but Blood Alcohol Concentration is sometimes used for simpler description. Blood alcohol content is usually expressed as a percentage of ethanol in the blood in units of mass of alcohol per volume of blood or mass of alcohol per mass of blood, depending on the country.
One way that society controls science is that the government can make certain experiments illegal. Hmm, maybe, but the apex answer is: People pass laws to restrict some research.
1 Socialism seeks to manage the economy through deliberate and collective social control.  Communism seeks to manage both the economy and the society by ensuring that property is owned collectively, and that control over the distribution of property is centralized in order to achieve both classlessness and statelessness.