What is the zero tolerance law?

How it differs from an ordinary DUI

The adult standard is 0.08 per cent, and the case usually involves proof of impairment. A zero-tolerance violation needs neither: the number alone is the offence. In many states it is handled as an administrative licence matter rather than a criminal charge, which makes it faster and easier to prove.

Typical consequences

• Licence suspension, commonly 90 days to a year for a first offence.
• Fines, alcohol education, and community service.
• Insurance consequences that often outlast the suspension.
• Where the reading reaches the adult limit, the full criminal DUI applies on top.

Where the numbers come from

0.02 per cent is low enough to be reached by a single drink for a light person, and it is also the level at which a cough syrup or a mouthwash argument starts to appear in real cases — which is why the type of test and its timing matter more in these cases than in adult ones.

Adjacent rules

Commercial drivers are held to 0.04 per cent nationally. Several states apply enhanced penalties above 0.15 per cent for adults, and many now treat a child passenger in the vehicle as a separate aggravating offence. A conviction as a minor can still appear on driving records used by employers and insurers years later, which is the consequence most families underestimate.