BOSTON — Congressional lawmakers are taking steps to restrict consumer access to a commonly available chemical compound that has been used by dozens of young people to kill themselves.

The bipartisan bill, filed by U.S. Rep. Lori Trahan, would limit the sale of any product with greater than 10 percent sodium nitrite by mass or volume. Only commercial businesses with a “verified” need could buy the higher concentrations.

The Youth Poisoning Protection Act would also require the product to be labeled with a warning about its fatal effects and details about antidotes. A similar measure passed the House last year, but stalled in the U.S. Senate.

“We are facing an urgent and troubling trend: the promotion of sodium nitrate — a toxic chemical — as a method to die by suicide,” Trahan, a Westford Democrat, said in remarks on the House floor Tuesday ahead of the bill’s passage.

Trahan said the measure, filed with Ohio Republican Rep. Mike Carey, is a “focused and reasonable” response to the problem that “targets bad actors who are exploiting a loophole to profit off tragedy, and it does so without burdening responsible businesses.”

Sodium nitrite is a chemical food additive typically used to process and cure meats like hot dogs, bacon and beef jerky to preserve shelf life and prevent the growth of bacteria, among other uses.

But in recent years the chemical compound has been promoted and popularized by online suicide forums as an easily accessible method to die by suicide.

“Most Americans have never heard of sodium nitrite, but for families who’ve lost loved ones, it’s something they’ll never forget,” Trahan said.

A New York Times investigation found that highly concentrated amounts of the poison were widely available on multiple e-commerce platforms, including with free two-day shipping on Amazon.

Following legal challenges and an outcry from lawmakers and victims’ families, Amazon and many other online marketplaces have removed sodium nitrite listings.

Amazon is fighting lawsuits filed by 28 families who lost loved ones who used sodium nitrite to die by suicide. They allege the company continued sell the chemical despite knowing of its misuse for suicide, an allegation Amazon denies.

In May 2023, a Canadian man was arrested and charged for shipping packages containing lethal amounts of sodium nitrite to over 40 countries, including 272 sales to individuals in the United Kingdom, of whom at least 88 people died, according to published reports.

At least four states — Washington, California, Colorado and New York — have approved legislation banning the sale of sodium nitrite.

A recent study published by the Journal of Clinical Psychiatry documented 172 suicides involving the use of sodium nitrate between 2020 to 2023. The group attributed the spike, in part, to online communities such as Sanctioned Suicide that share online recommendations to assemble “suicide kits.”

“These forums often give detailed instructions regarding how to procure, prepare, and administer sodium nitrite for suicide,” the report’s authors wrote. “They can create potentially harmful environments where people in emotional distress may promote risky behavior and encourage each other to act on harmful impulses.”