Hennepin County has enacted a ban on electronic cigarettes that is more restrictive than state law.

The policy, approved by the County Board on Tuesday, prohibits the use of "electronic delivery devices" — e-cigs — in all indoor spaces governed by the Minnesota Clean Indoor Air Act.

The ordinance will take effect March 10. The lone dissenting vote was Commissioner Jeff Johnson.

State law bans e-cigs in some, but not all, indoor places. In 2014, the Legislature banned e-cigs in government buildings, public schools, day care centers and most health facilities, but stopped short of treating them like actual cigarettes.

Hennepin County is joining several other Minnesota communities that have moved to expand the ban on e-cigs to all places where smoking tobacco is prohibited under the more restrictive Clean Indoor Air Act, such as restaurants, buses, stores and offices.

The city of Minneapolis recently banned e-cigs in restaurants, offices and other public spaces. It also doesn't allow the devices in city-owned facilities and vehicles.

E-cigarettes are battery-powered cartridges that heat up flavored liquid and produce an inhaled nicotine vapor. Many e-cigarette users, or "vapers," use them as a lower-nicotine alternative to cigarettes, or as a bridge to quitting cigarettes altogether.

While many people claim they are far safer than conventional cigarettes, health officials say their long-term effects are not yet clear.

The board held a public hearing on the ordinance passed Tuesday on Jan. 13.