3M is nearing a settlement to resolve more than 300,000 claims from U.S. veterans over the company’s combat arms earplugs. The complaints allege the earplugs, which were supplied to the U.S. military, did not adequately protect soldiers from hearing loss.

People close to the discussions told The Wall Street Journal that under the terms of the proposed settlement, 3M would pay about $5.5 billion. The 300,000 claims make the earplug litigation the largest mass tort claim in U.S. history.

The earplugs, which were developed by Aearo Technologies, were designed to protect users’ hearing from loud noises like explosions while allowing voices or other softer noises to be heard. The veterans claimed the earplugs were defective and failed to protect them from noise damage.

3M has pushed back against the claim, saying the earplugs work when used correctly.

In 2018, 3M agreed to pay $9.1 million to the U.S. government to resolve allegations that the earplugs could loosen in one’s ear without them noticing.

Aearo filed for bankruptcy in the summer of 2022, accepting responsibility for all the liability claims. The filing was dismissed by a bankruptcy court judge, who ruled Aearo didn’t qualify for bankruptcy protections.

3M’s ability to pay a multibillion-dollar settlement to veterans may be hampered after the company came to a tentative agreement to settle litigation over so-called forever chemicals in city drinking water. That agreement could cost 3M as much as $12.5 billion over five years.

“We don’t like the overhang on the stock and we want to manage it, but we’ve got to, as we move forward, do what’s in the best interest of the company for the long term,” 3M Chief Executive Mike Roman told the Journal in July of 2023.