The measure, sponsored by Rep. Patrice Arent. a Democrat, has been approved 6 to 2 by the House Health and Services Committee and now goes to the full House for debate, The Salt Lake Tribune reported Tuesday.
The bill would prohibit smoking in company vehicles while a child age 15 or under is present.
The ban would apply to vehicles shared by employees, but not to vehicles used solely by the owner-operator of a business.
Violators could be fined up $45, which could be waived if the person enrolled in a smoking cessation program.
The Utah Department of Health reported in 2010 that 16,000 of Utah's children suffering from asthma were exposed to secondhand smoke while in a car.
Speaking about the bill before the committee, Arent said, "I don't take lightly telling the public what they can do in their cars unless it is for a very important health or public safety purpose like the one we have here today."
Dalane England of the Utah Eagle Forum argued against the bill, telling members of the committee "I don't really believe this bill is about cars or smoking. This bill is about who is the best parent; it's about our freedom versus our security."