When the Toxic Substances Control Act was first introduced in 1976, it was one of the most forward-thinking laws of the time, according to Travis Wagner, a professor of environmental science and policy at the University of Southern Maine.

“The problem was that its implementation was so poorly designed,” he says.

The Toxic Substances Control Act (TSCA) was designed to allow the Environmental Protection Agency (EPA) to oversee and regulate chemicals used in the United States. It didn’t cover chemicals used in pesticides, cosmetics, food, and pharmaceuticals — those are regulated under different laws — but it covered the chemicals used in everything else, from water bottles to couches to cleaning products. Before the TSCA, there was only limited oversight of industrial chemicals.

But the TSCA had a number of critical flaws. For one, the EPA had to consider the economic effects of regulating a chemical (which was part of the reasoning that prevented the ban of asbestos in 1991), allowing cost to trump health. Additionally, there weren’t any time limits for an EPA investigation into a chemical. And most egregious, the original TSCA grandfathered in about 62,000 chemicals that were already in use in industry, essentially declaring them safe without any testing.

“A lot of people in the profession have seen it as a failed law,” says Wagner. But in July 2016, the law got a much needed update with the Frank R. Lautenberg Chemical Safety for the 21st Century Act.

The new law fixes a number of weak points in the original TSCA. It adds deadlines and removes economic considerations. It explicitly states that chemicals used for consumer products have to be assessed in vulnerable populations, like children and the elderly, as well as all other populations that could come into contact with it. It also requires that the EPA begin testing all 62,000 chemicals grandfathered in under the previous version of the TSCA.

“The EPA has always had this list of chemicals they were concerned with, but they couldn’t do much about them,” said Wagner.

By mid-December, the EPA must be in the process of reviewing 10 chemicals. In three and a half years, they must be doing evaluations on 20. They’ll start with the chemicals of highest of concern to human health, and work down from there.

It will be a slow process — the EPA has up to three years to gather data and conduct studies on each chemical, and there are thousands of chemicals still in use by industry that they need to test — so it could be some time before regulations or restrictions take hold.

Wagner says, though, that there are some things that could expedite the process. He says that some chemicals that have already been studied quite a bit and already have some regulations in place, like lead and BPA, will probably move through the process more quickly.

“If they were just starting from scratch, it takes a long time,” he says, “but there’s a lot already done with [some chemicals].”

The EPA will also announce the chemicals that are under review in advance. Hopefully, this too will expedite the process as the threat of a review can be enough to spur companies to make changes in chemical uses — particularly if consumers begin to demand that those changes be made. For example, Walmart called for its suppliers to stop using certain controversial chemicals back in July, without any government regulation, solely on the basis of consumer concerns and research that eventually led to some chemicals being banned altogether this fall.

“[Manufacturers] can be proactive. If it’s a consumer-based product, they’re going to be proactive. Otherwise it’s going to be a disaster for them,” says Wagner. “The consumer is going to put the pressure [on manufacturers], and that’s going to have a much more profound impact than a law.”

Even with the most potentially harmful chemicals prioritized in the first wave of evaluations, changes to chemical use and regulation aren’t going to happen overnight. Wagner says that the soonest changes might begin to appear in a few years. The Lautenberg Act sews up holes in the government’s oversight of chemical usage, but direct impact on consumer product is still a ways off.

Nicole is a science writer based in New York. She tweets @NicoleWetsman, mostly about neurons and women's soccer.