The new law — which went into effect Jan. 1 — bans those under 21 from buying tobacco products, including electronic cigarettes.

Most smokers start smoking before age 21, and about half become daily smokers before 18, the Hawaii State Department of Health said in a press release.

While smoking has decreased greatly in Hawaii, use of e-cigarettes is on the rise. 22% of high school students have tried e-cigarettes, compared with only 5% in 2011, according to the same release.