Holland & Knight, one of Washington’s most lucrative lobby shops, has hired two former top congressional aides who helped draft a sweeping new law that changes the way the government regulates chemicals — a signal that K Street sees the law as an opportunity to capture new business.

Ben Dunham and Dimitri Karakitsos were once adversaries who are now working under the same roof. Dunham was a top adviser to the late senator Frank Lautenberg (D-N.J.), after whom the law was named, and Karakitsos was his Republican counterpart, working as the senior staffer for the Senate Environment and Public Works Committee. For five years starting in 2009, as their bosses fought over what the bill should include, Dunham and Karakitsos worked together to organize hearings, briefings and meetings with industry groups to weigh in on the measure. They drafted an early version of what would later become the basis of the legislation that became law in June.

Environmental lobbyist Rich Gold, who leads Holland’s $20 million-a-year lobbying department, had a front-row seat to the action, as he lobbied on behalf of chemical companies seeking to shape the legislation. Gold recruited Dunham, who joined the firm over the summer, and Karakitsos, who starts Monday. Dunham had been working at another firm, Dentons, since 2014. Karakitsos comes directly from the Hill.

“It was always something we had our heads down and were working really hard on, me from the lobbying side and Ben and Dimitri on the Hill,” Gold said. “This is in some sense getting the band back together again.”

The Frank R. Lautenberg Chemical Safety for the 21st Century Act, which amends the Toxic Substances Control Act (TSCA), was signed into law by President Obama in June. The law gives the Environmental Protection Agency more authority to evaluate the safety of chemicals that go into nearly every product sold to consumers, including paint, cleaners, detergent and cars.

Dunham and Karakisos are now advising Holland’s corporate clients — chemical manufacturers, trade groups for consumer products, and retailers — in influencing how the EPA will implement the law.

“We have the folks that were there at the birth of the baby and know the history and have good relationships with the EPA and the folks that will be implementing the law and know where things should be headed,” Gold said.