<P> The term is used in the context of driving under the influence of alcohol, referring to a lower illegal blood alcohol content for drivers under the age of 21 . In the US, the legal limit in all states is now . 08%, but for drivers under 21 the prohibited level in most states is . 01% or . 02% . This is also true in Puerto Rico despite a drinking age of 18 . </P> <P> In Europe, Belgium, Finland, France, Germany, and Sweden have zero - tolerance laws for drugs and driving, as opposed to the other main legal approach where laws forbidding impaired driving is enacted instead . The legislation among countries that practice zero tolerance on drug use for drivers varies . Only a limited set of (common) drugs are included in the zero - tolerance legislation in Germany and Belgium, where in Finland and Sweden all controlled substances fall into the scope of zero tolerance, if they are not covered by a prescription . </P> <P> In Argentina, the Cordoba State Highway Patrol enforces a zero - tolerance policy . </P> <P> In Asia, Japan also practices zero - tolerance for alcohol and driving . The people caught driving after drinking, including the next morning if there are still traces of alcohol, receive a fine and can be fired . Foreigners may even be deported . </P>

When was zero tolerance policing introduced in the us