In the United States and Canada, zero tolerance policies are applied in schools and other education venues. These have proved controversial in that some of those penalized have claimed that their treatment is egregiously unfair.
A zero-tolerance policy is a policy of having very little tolerance for transgressions: any infraction of existing laws and regulations will be punished, no matter how small. The term may be used in general or with reference to a particular category of transgressions, e.g. a zero-tolerance policy towards alcohol use.
It is typically enacted by an organization (usually a school) against a particular action, or possession of something on organization-controlled property. Many schools have a zero-tolerance policy concerning drugs or weapons. For example, a student possessing or caught using drugs on school property governed by a zero-tolerance policy could immediately suffer the highest possible consequence for their actions. Many organizations avoid these policies because it binds those in authority to an action, regardless of circumstances. The policy must be written extremely explicitly or it may have negative consequences.
As of 2004 many publicized cases have sparked slight controversy with regards to (at least what some perceive as) irrationality of the policies. These cases include students being suspended or expelled for transgressions such as carrying Advil (a legal, non-prescription drug) in backpacks, keeping pocketknives (small utility knife) in cars, and carrying sharp tools outside of a "wood shop" classroom (where they are often required materials). In some jurisdictions, zero-tolerance policies have come into conflict with freedom of religion rules already in place allowing students to carry, for example, kirpans.
Most policies were enacted after the shootings at Columbine High School in Littleton, Colorado. One well documented case took place in the Ashland, Oregon School district.