The full Senate opened debate Tuesday on the legislation, which would fine drivers as much as $50 if they or a passenger are caught smoking in a vehicle with a passenger 8 or younger.
The House Environmental Matters Committee heard testimony Tuesday on a similar bill.
Sponsors say the bill could reduce the number of long-term illnesses caused by secondhand smoke, but opponents argue the state could be overstepping its boundaries by restricting motorists’ behavior inside their own vehicles.
“It just doesn’t make much sense to me,” said Sen. Edward R. Reilly, Anne Arundel Republican. “This is just another opportunity for police officers to impose themselves in our daily lives.”
The Senate bill, sponsored by Sen. Jennie M. Forehand, would consider smoking with a child to be a primary offense, allowing police to pull over a motorist who is otherwise obeying all other traffic laws. However, the offense would not be considering a moving violation.
Several states have adopted similar bans for vehicles carrying children as old as 17.
Mrs. Forehand, Montgomery Democrat, cited studies that have linked secondhand smoke to asthma and other lifelong illnesses in children and said a ban would help to protect youths while also curbing the state’s medical costs.
“It is a real problem,” she said. “The cost of medical care is going to go up if we don’t protect these kids when they are 8 and under.”
Her bill was approved last week by the 11-member Senate Judicial Proceedings Committee, which rejected the same proposal last year. Two Democrats and one Republican who voted against last year’s bill supported this year’s.
Sen. Robert A. Zirkin, Baltimore County Democrat, said he was swayed by recent medical studies that have found secondhand smoke to be more harmful in cars than in most other areas, sometimes reaching toxicity levels 10 times greater than those deemed acceptable by the Environmental Protection Agency.
“Obviously everybody understood that this was bad for you but now there’s hard science behind it,” said Mr. Zirkin, Baltimore County Democrat. “These kids have zero choice and they are being poisoned.”
Nonetheless, critics have raised questions about enforcing such a law, arguing that it could lead police officers to erroneously pull over drivers carrying a child car seat but not a child.
They have also predicted the law could pave the way for in-home smoking bans or other restrictions on parental behavior.
“There’s not one good reason to smoke in a car with your kid, but that’s not the question,” said Sen. James Brochin, Baltimore County Democrat. “The question is how much do we regulate the relationship between a parent and child?”