Looks like some schools are giving e-cigarettes a big, fat "F."

Most school districts in the U.S. have met the growing popularity of e-cigarettes among students by including the devices, sometimes also known as vaporizers, in their anti-tobacco policy.

Schools in four states, however, are treating e-cigarettes as drug paraphernalia, which carries harsher penalties than detention or a sternly-worded letter home to parents.

Schools in North Carolina, New Jersey, Washington and Connecticut are grouping "e-cigs" in with bongs and pipes, meaning students could face long suspensions, required drug tests and have "possession of drug paraphernalia" on their school record.

The devices, which heat a nicotine solution to create a vapor, have surpassed traditional cigarettes in popularity among teenagers.

School officials say they can't be sure if a student is using a nicotine solution or an illegal substance, such as hash oil or marijuana.

Watch the clip above.