Mayor Kirk Caldwell is expected to sign a bill approved by the Honolulu City Council making it illegal on Oahu to smoke in automobiles when children are present.

The nine-member Council voted 8-0 Wednesday to pass Bill 70, which would apply not just to tobacco products, but also to e-cigarettes and other electronic smoking devices. Councilman Joey Manahan was on the mainland attending a conference and was not present for the vote.

Caldwell told the Honolulu Star-Advertiser in August that he likely would sign the bill, provided it passes a standard legal review by city attorneys.

Introduced by Council members Brandon Elefante and Ron Menor, the key argument in support of the measure has been that children under 18 usually have no choice when it comes to riding in a vehicle driven by adults.

Critics contend that the bill is overregulation and a further intrusion into people’s private lives. Some also have questioned how the new law will be enforced. But a number of people at Wednesday’s Council meeting testified in favor of the measure.

Lila Johnson, program manager for the state Department of Health’s Tobacco Prevention and Education program, said studies have found no level of second-hand smoke is safe and that simply recommending adults refrain from smoking in cars when children are present has been unsuccessful.

“If this becomes law, it would certainly require a strong public education campaign,” Johnson said. The Heath Department stands ready to help that effort, she said.

Jaylen Murakami, a member of the Coalition for a Tobacco-Free Hawaii, said in the confined spaces of a car, “smoke can rapidly reach toxic levels and create a health hazard, even when the windows are open.”

Also supporting the ban were the American Heart Association, the American Lung Association, the Hawaii COPD (Chronic Obstructive Pulmonary Disease) Coalition, the Community Health Outreach Work project and the University of Hawaii Student Health Advisory Council.

In written testimony, representatives from the Hawaii Smokers Alliance and Volcano Fine Electronic Cigarettes were opposed to the restriction.

Cory Smith, Volcano’s owner and CEO, said the ban links vapor devices with regular cigarettes even though they contain no tobacco, produce no smoke and have not been proven to have the same adverse effects of tobacco products.

The Honolulu Police Department did not support or oppose the bill, but an HPD captain testified before the Public Health, Safety and Welfare Committee that HPD did not anticipate problems with enforcing a ban.

Hawaii County has had a similar ban in place since 2010, while Kauai County prohibited smoking in a vehicle with children under 13 in July 2016.

Efforts to impose the ban statewide have been unsuccessful. Most recently, Senate Bill 261 was approved by the state Senate only to fail without a hearing in the House.

Nationally, eight states and Puerto Rico have statewide bans for children of varying ages. Bans in counties and cities in five states align with the ban that would take effect on Oahu, Elefante’s staff found.