SALEM, Ore. (AP) -- Drivers caught talking on their cellphones are losing the ``I have to use it for work'' excuse next week.

That loophole in Oregon's phoning-while-driving ban will be eliminated, one of dozens of new laws that take effect in the new year. Come Sunday, people who solicit underage prostitutes will face steep fines, possessing shark fins will be illegal, and drunken drivers will have to get a breath-test machine installed in their car.

Some police officers have complained that it's tough to enforce Oregon's ban on using handheld cellphones behind the wheel because of a vague provision that allows driving and talking if it ``is necessary for the person's job.'' Legislators intended it as an exemption for law enforcement and emergency workers, and some judges interpreted it that way. Others were more lenient and dismissed citations issued to people in other professions.

The new law says only emergency responders and roadside assistance workers like tow truck drivers can use a handheld phone. That's a much clearer rule, said Kevin Campbell, a lobbyist for the Oregon Association of Chiefs of Police.

``Our belief is that any law should be as clear as possible so people can obey it and officers can enforce it,'' Campbell said.

Anyone can hold their phone to call 911, and talking with a hands-free device is still legal. The maximum fine remains $90.

Another law taking effect Sunday will require anyone convicted of drunken driving, even first-time offenders, to get an ignition interlock device installed in their cars. The machines check a driver's breath before the engine will start, and periodically while driving to keep it running.

Interlocks are already required for many drunken drivers, but first-time offenders are often sent to diversion programs instead of jail.

``Once you're on diversion, we thought that having this tool would help them keep from re-offending,'' said Chuck Hayes, a retired state police captain who chairs the Governor's Advisory Committee on Driving Under the Influence of Intoxicants.

Police will get a new tool to crack down on child sex trafficking next year, when the penalty for offering to pay for sex from a minor will be a $10,000 fine the first time and $20,000 for a second offense. Perhaps even more significant, prosecutors won't have to prove that a defendant knew the victim was underage.

The change is part of an effort to combat sex trafficking by cracking down on ``johns'' who solicit sex from prostitutes.

In a bid to stop demand for illegally killed sharks, it will be illegal to possess or sell shark fins in Oregon. Shark fins soup is a Chinese delicacy.

The minimum wage will go up 30 cents to $8.80 an hour.

Oregonians who make more than $125,000 a year -- $250,000 for joint filers -- will see some tax relief as top tax rates drop under voter-approved Measure 66. The new rates will be lower than they've been for the last three years but still higher than they were before Measure 66 was enacted.