“My heartburn with this isn't the intent or the good that will come from it, but justifying moving into the domain of private property rights in an effort to do the right thing,” said Sen. Darin Peterson, R-Nephi.

Sen. Scott McCoy, D-Salt Lake City, said a child trapped in a car with a smoker can't escape the harmful air and is more susceptible to damage from the smoke. His bill would make it illegal to smoke in a car carrying a child 5 years old or younger.

“This bill is an attempt simply to address an issue that is of great importance to those kids,” McCoy said.

The crime would be a secondary offense, meaning a driver couldn't be stopped just for smoking with a child in the car, but could be ticketed if the car is speeding or being driven recklessly, for example. It would be punishable by a $45 fine.

The bill was given preliminary approval by a 20-9 vote, but nearly half of those voting for the bill expressed some reservations about the measure, meaning its final passage today is not assured.

“As parents, we are accountable for the things to which we expose our children,” said Sen. Mark Madsen, R-Lehi, one of the nine who voted against the measure. “But I don't believe that government is the entity to which we are accountable for these things. I believe we are accountable to a higher authority and interjecting government at this point is probably well intentioned, but misplaced.”

Other senators questioned how law enforcement could enforce the bill, since proving a child's age is difficult.

The Senate passed a similar bill last year, but it failed to get through the House.