WASHINGTON -- More than three years after a Wisconsin van crash killed seven teenagers who were selling magazines door-to-door, the Senate this week approved legislation to bar young people from joining traveling sales crews.

Spearheaded by Sen. Herb Kohl, a Wisconsin Democrat, the bill would prohibit anyone under the age of 18 from working for door-to-door peddling groups that spend more than 24 hours at a time on the road. The Senate unanimously passed the bill Thursday evening, shortly before leaving Washington for a month-long recess.

"I'm pleased that we have made progress in going after the bad actors in the traveling sales industry," Kohl said.

The van crash near Janesville focused national attention on the tens of thousands of young people who are lured into the door-to-door magazine-selling business.

Lawmakers and anti-child-labor activists say that the teenagers often become "indentured servants" who are forced to work 14-hour days and stay away from their homes for weeks on end, all the while receiving minimal pay.

Investigations into the multimillion-dollar industry have found that the young workers often are physically and verbally abused by their bosses and customers. Over the past decade, dozens of traveling magazine peddlers, primarily young people, have died in car accidents similar to the one that occurred in Janesville.

While the practice has been the subject of congressional hearings dating back at least 15 years, Congress has never approved legislation to address industry abuses.

Experts on the traveling sales groups say Kohl's bill has been watered down and will not solve the problem.

When Kohl first introduced a bill in early 2001 to outlaw the practice, it also would have required that workers in door-to-door sales industries be paid the minimum wage and overtime compensation.

"Covering these employees with minimum wage laws and overtime requirements protects them from becoming indentured servants to their employees through complex compensation systems," Kohl wrote in March 2000 to other senators, urging them to support his legislation.

But that provision -- along with another one creating a federal licensing system to monitor door-to-door sales operations -- was removed from the final version of Kohl's bill.

Earlene Williams, the director of Parent Watch, a New York City-based group that has been monitoring the issue for decades, blasted Kohl for "abandoning ship" and pushing a "gutted" piece of legislation.

She said people should have to be at least 21 years old, not 18, to join the sales teams. A higher age requirement "would sharply reduce the kinds of physical and emotional abuse salespeople have reported," Williams said.

Darlene Adkins, vice president of the National Consumers League and coordinator of the Child Labor Coalition, called Kohl's bill "a good first step." But she said the deletion of the federal monitoring provision meant that state and local governments still would have trouble tracking the peddling rings, which roam across state lines to avoid detection.

"It's a very hard industry to keep your eye on," she said. "The fact that the enforcement provisions were taken out is unfortunate. Adkins also said the legislation ignores "a whole other dimension" of children peddling products, such as so-called "candy kids" who hawk chocolate bars on street corners. Many of them are only 10 years old and their bosses and customers often abuse them. Kohl's bill would not apply to them because they usually return home each night.

Lynn Becker, Kohl's spokeswoman, said the senator agreed to change the bill to gain support from Republican lawmakers. She said the legislation would be effective even in its modified form.

The bill still faces hurdles in the House, where Rep. Tom Petri, a Fond du Lac Republican has introduced similar legislation. Before voting on it, lawmakers probably will want to hold hearings, a process that some aides say is unlikely to be completed this year. "You're up against a real time crunch," said an aide to Petri. "I'm not sure it's going to clear this Congress."