A Natrona County man is suing 3M and a subsidiary, claiming that earplugs he used while in the Navy did not properly function and left him with permanent hearing damage.

In a personal injury lawsuit filed in federal court Monday Natrona County resident Steven Mayo alleges that monetary damages have not been determined but exceed $75,000. Mayo joined the U.S. Navy in 2003 where he worked in construction, eventually reaching the rank of builders second class. He was honorably discharged in 2014, according to the complaint.

Mayo served two tours in Afghanistan and two tours in Iraq, according to the lawsuit. Documents in the lawsuit indicate he resides in Natrona County.

"Plaintiff was issued a pair of Combat Arms earplugs while in Iraq," the lawsuit says. "Plaintiff underwent two tours in Iraq and two tours in Afghanistan where he was a member of the U.S. Navy SEABEES. During his deployment to Iraq and Afghanistan and during military training and combat exercises, plaintiff was continuously exposed to loud noises and explosions."

Mayo's lawsuit comes amid a flurry of lawsuits against 3M nationwide in which veterans, who used dual-ended Combat Arms earplugs, are claiming they now suffer from tinnitus, a condition that leaves them with a continuous ringing in their ears.

Jason Ochs, Mayo's attorney in the lawsuit, could not immediately be reached for comment.

The earplugs were manufactured by Aearo Technologies until the company was acquired by 3M in the early 2000s. 3M continues to maintain Aearo as a separate operating unit, according to the lawsuit.

Aearo became aware of the earplugs' defects as early as 2000 but still sold them to the military, the lawsuit alleges.

Combat Arms earplugs had a yellow and green end which denoted how they were to be worn.

According to the lawsuit, Combat Arms earplugs could be worn in an open or unblocked position with the yellow end inserted which would reduce loud sounds like gunfire and explosions yet allow servicemen to hear quieter sounds such as commands and approaching enemy combatants.

They could also be worn in a closed or blocked position with the green end, the suit says, which would reduce all sounds and operate as normal earplugs.

However, the earplugs had a "dangerous design defect" that caused them to loosen in wearers' ears regardless of how they were worn.

"Because the defect was imperceptible to the wearer, [Aearo's] design defect went undetected for more than a decade by the U.S. military and those who wore them. It is thus not surprising that hearing damage is now the largest ongoing medical cost the military incurs each year," the lawsuit says. "The VA thus spends more than $1 billion per year to treat hearing damage suffered by more than 800,000 servicemen."

In 2018, the U.S. Department of Justice announced that 3M agreed to pay $9.1 million in response to claims that it knowingly sold Combat Arms earplugs to the U.S. military despite being aware of their defects.