Illinois regulations that require staffing firms to provide temporary workers equal pay compared to directly employed workers was signed into law by Illinois Gov. JB Pritzker on Friday.

The regulations affect only industrial contingent workers, and the provision related to equal pay for contingent workers is similar to a New Jersey law that took effect Aug. 5. However, the Illinois law’s equal pay regulations take effect only after a contingent worker has been on a worksite for 90 days, which was added after lobbying by the American Staffing Association.

Right now, there are worries within the staffing industry over what the exact final regulations in the law will be; they have not been released even though the law has taken effect.

“Our biggest concern is that there are still a lot of questions in regards to interpretations and definitions that we have to answer in order to implement this,” said Toby Malara, VP, government relations at the American Staffing Association.

There are questions over how to implement equal pay and how to define similar work, Malara said. There are also questions over cost of benefits, including what kinds of benefits are covered.

Malara said the ASA has reached out to Illinois about holding off enforcement of the law until final regulations are in place but has not heard back yet.

Right now, staffing firms may have conversations with clients and get systems in place as much as possible, he said.

There is also concern similar legislation could spread to other states. Already, Maine has an intent bill that aims to create a temporary worker right-to-know law, but that bill does not yet have any formal wording, Malara said. An intent bill is one that states the intent of the legislature.

In the Illinois law, the official wording that calls for equal pay reads in part:

“Equal pay for equal work. A day or temporary laborer who is assigned to work at a third-party client for more than 90 calendar days shall be paid not less than the rate of pay and equivalent benefits as the lowest paid directly hired employee of the third-party client with the same level of seniority at the company and performing the same or substantially similar work on jobs the performance of which requires substantially similar skill, effort, and responsibility, and that are performed under similar working conditions.”

A worker group called the Chicago Workers Collaborative lauded the bill and said it passed the Illinois Senate by a bipartisan 49-3 vote and the Illinois House with a 72-36 vote.

Legislation sponsor Rep. Edgard Gonzalez, D-Chicago, said in a Chicago Workers Collaborative press release that the regulations will mean an average of $4 more per hour for thousands of contingent workers in his district.