MINNEAPOLIS (AP) — The Hennepin County Board has approved a ban on electronic cigarettes in workplaces, restaurants and bars.

The board approved the policy by a 6-1 vote Tuesday. The policy prohibits the use of "electronic delivery devices" in all indoor spaces governed by the Minnesota Clean Indoor Air Act.

The ordinance takes effect March 10.

Hennepin County's ban is more restrictive than state law. State law currently bans e-cigs in some, but not all indoor places.

Many e-cigarette users, or "vapers," use them as a lower-nicotine alternative to cigarettes, or as a bridge to quitting cigarettes altogether. Health officials say the potential long-term effects of e-cigs are not yet clear.