LOS ANGELES (AP) — The U.S jewellery industry wants states to overturn laws that limit the toxic metal cadmium in children’s trinkets and adopt new voluntary guidelines it helped create, saying stricter rules in several states create chaos for manufacturers and importers.

Persuading legislators to reopen the issue won’t be an easy sell: Many consumer and environmental advocates say the new guidelines weaken protection of children’s health.

While the voluntary rules have the support of federal regulators, states that passed much stricter limits over the past year would have to backtrack and allow higher levels of a metal that can cause cancer.

That didn’t sound likely Monday.

“Maryland ought to set whatever standard we feel is correct,” said Delegate James Hubbard, a Democrat who successfully sponsored the nation’s toughest cadmium-in-jewellery limits this spring. “We made a judgment call based on what we felt was in the best interest of the people we represent.”

A jewellery industry that has been hammered by more than a year of recalls and legal setbacks does have some momentum, now that the rules it drafted were passed last week by the respected organisation ASTM International, which sets voluntary rules for a range of goods. Industry’s goal is to replace the current patchwork of regulation with a unified standard.

“Our whole mission in this is to have standards that are not floating in quicksand,” said Brent Cleaveland, head of the ASTM subcommittee that wrote the rules and executive director of the Fashion Jewellery and Accessories Trade Association. He described the limits he oversaw as “way more conservative than necessary” to protect kids’ health.

Cleaveland says his next move is to press legislatures in states that have set limits to reopen the issue and adopt the voluntary standards. If that succeeds, Cleaveland would then ask Congress to pass legislation to make the voluntary standard national law.

If the industry lobbying effort fails, state limits that are much tougher than the voluntary rules will effectively remain the national standard. That’s because manufacturers that sell in places like California and Maryland would need to comply with limits there, and wouldn’t create different products for the rest of the country.

Mandatory limits adopted over the past year already deter use of the heavy metal, which over time can also cause bone and kidney diseases, though there have been no documented deaths or serious injuries.

While the voluntary standards don’t trump limits from states and legal settlements, they do create a consensus national standard that jewellery manufacturers and importers endorse.

Because the limits are voluntary, there is no automatic penalty for jewellery sold with cadmium levels exceeding them. The U.S. Consumer Product Safety Commission will, however, use the limits in deciding whether to pursue product recalls.

The agency has argued that voluntary limits were the appropriate — and fastest — way to create a common understanding of what constitutes a problem piece of jewellery. The agency said that unless it finds widespread failure to comply, it will not seek mandatory rules.

In response to an Associated Press investigation, the Consumer Product Safety Commission helped recall about 300,000 pieces of high-cadmium necklaces, bracelet and rings last year. The AP reported that some of the jewellery contained more than 90 percent cadmium and would release alarmingly high levels of the metal into stomach acid if swallowed.

Problem jewellery, typically made in China, was available across the marketplace, from Walmarts to chain stores specializing in jewellery to dollar-type shops.

Five recalls were done before the agency decided how to handle the problem. By last fall, guidelines were in place for how to identify a hazardous piece of jewellery based on lab testing that mimicked how much cadmium would enter a child’s body from jewellery that was licked or swallowed. In that process, the agency more than tripled its estimate of how much cadmium a child could safely ingest.