Ten days ago, with President Obama's signing of new chemical safety legislation, the last remaining environmental legislation of the 1970s that had not been updated got a makeover.

It had been a long time coming.

More than 80,000 chemicals are in common use, and previously the U.S. Environmental Protection Agency could call for safety testing only after evidence that there was a potential danger. As a result, the EPA has been able to require testing on only about 200 chemicals. It has regulated or banned just five.

Getting new legislation was a priority for U.S. Sen. Frank R. Lautenberg (D., N.J.), who had worked on it since 2005. Shortly before his death in 2013, when it began to look as if political compromise might be possible, he released a statement saying that "American families deserve to know that the chemicals found in everyday products are safe. But because of our broken laws, toxic chemicals that have been linked to cancer and other serious diseases make their way into our homes on a daily basis."

The new law - actually, a series of amendments - pays tribute to him with its name: the Frank R. Lautenberg Chemical Safety for the 21st Century Act.

It passed overwhelmingly, though industry representatives view it as too harsh. Environmental and public health groups say it is too lax.

Michael Gochfeld, professor emeritus in Rutgers University's Environmental and Occupational Health Sciences Institute, recently spoke to us about the act.

Why was it so important to update the original Toxic Substances Control Act, or TSCA?

TSCA was a very important development in the 1970s. It was really landmark in its concept, but unfortunately hamstrung in its implementation. Under TSCA, the National Toxicology Program conducted many studies of many chemicals to assess their carcinogenicity. But the other aspect, which included EPA's promised role in evaluating existing chemicals and new chemicals, simply couldn't materialize. There were too many restrictions with regard to what EPA could actually accomplish - for example, banning chemicals that were considered hazardous.

Everybody seemed to agree that it wasn't an effective law. All the other 1970s environmental laws had been amended or addressed, except for TSCA.

What are some of the most important things the new legislation achieves?

The amendments free up EPA to do many of the things that were promised. It also imposes on EPA the requirement to identify susceptible populations and to make sure that they are protected. That would be children, pregnant women, the elderly and workers. The workers were the particularly novel component that I was surprised to find in the bill. It requires EPA to identify high-priority chemicals and to evaluate their hazards. And, in some cases, to evaluate particular uses of a chemical. So EPA might ban a chemical for one application, while allowing it for another.

Also, the amendment sets up a fund that industry has to pay into to actually fund this function of the EPA. There was no such funding under the original TSCA. This is a major change. I think it will certainly protect this part of EPA's responsibility.

What are the biggest failures of the new legislation?

One of its most controversial provisions is that states that are more restrictive or protective than the federal government might have their actions on hold while the EPA is in the process of evaluating a high priority chemical. They cannot take any new action on a chemical once EPA has said that it is going to list it as a high priority chemical and evaluate it. It's a preemption issue. But although that was very controversial, in reality it doesn't amount to much because EPA can only designate a few chemicals as high priority at one time. Ideally, it would work on about 25 chemicals. Its capacity to go beyond that is limited. It's an expensive, labor-intensive, information-intensive activity. EPA simply doesn't have the staff or the funding.

Another controversial issue - no one knows quite how it will play out, but it allows for some mischief - is that manufacturers can request that EPA review a particular chemical. So that could be a good thing. The manufacturer could learn whether a particular chemical it is proposing to use is problematic. Or, manufacturers could load up EPA's calendar with chemicals that it would not have chosen of its own accord. It seems to be a loophole for nuisance chemicals. Or, suppose I could request that the EPA review a competitor's chemicals. It's not clear whether that would be possible.

The EPA administrator has a lot of leeway in the amended act. So a really good, conscientious, on-top-of-everything administrator could make the act work. A less-good administrator could let the act languish and focus attention on chemicals that aren't really that critical, from a public health perspective.

Ultimately, will Americans be safer because of this act?

In the long run, I think the answer is yes. If it's well-publicized and manufacturers or importers know that people will be watching, then I think there will be less opportunity for importing dangerous pesticide residues, or adding certain compounds to paints or plastics. Some things are not covered: Cosmetics are not included because they are covered by the U.S. Food and Drug Administration. But from a toxic chemical perspective, they could still be important.

But nothing is going to change overnight. The EPA has to identify a certain number of high-priority chemicals for review in the first 18 months. Then it has three years to review them. Then, if it decides the chemical poses a public health or environmental hazard, it has two more years to recommend how to solve the problem. In that, an important benefit of the amendment is that in the previous act, when EPA wanted to regulate something, it had to go through every possible regulatory approach, including taking into account cost. The amended act gives EPA much more latitude in how it can regulate a chemical, based on health alone. That's a really big advance and a big advantage. It frees up the EPA to regulate, where before its hands were very tightly tied.

Is there opportunity for public involvement at this point?

There is clearly a role for public involvement. EPA has to establish policies, it has to come up with a protocol for how it's going to evaluate the chemicals, and it no longer has to know at the outset how dangerous something is. It is allowed to investigate that. Another part of the act is that EPA has to keep the public informed. It has to have a report every year to Congress on its progress in identifying high-priority chemicals and conducting what they're calling a safety assessment. If the public is engaged, the new act will be more effective.