The Judicial Panel on Multidistrict Litigation (JPML) has decided to consolidate and centralize all military earplug lawsuits against 3M pending in the federal court system due to striking similarities in the allegations that the standard U.S. military issue Combat Arms earplugs’ significant defects caused permanent hearing damage.

More than 635 military earplug lawsuits have been filed nationwide in 33 different District Courts during the past few months due to veterans developing hearing loss and tinnitus from the earplugs.

The plaintiffs all allege they developed hearing loss after military service due to the defective earplugs. Experts predict that thousands of additional cases are likely to join the litigation in the future.

Aearo Technologies originally introduced the Combat Arms Earplugs, Version 2 (CAEv2) before 3M acquired the company. Aearo designed the reversible earplugs to serve as traditional earplugs one direction and provide filtered noise reduction in the other direction. The manufacturer indicated this would block loud battlefield noises while still allowing the wearer to hear verbal commands. They were standard issue for the U.S. military between 2003 and 2015.

According to the military earplug lawsuits, the manufacturer knew for years that earplugs were too short to properly seal the ear canal. Consequently, this left military service members without adequate hearing protection.

Earlier this year, plaintiffs filed a motion to transfer all the cases to one District Court to avoid conflicting pretrial rulings and orders from various federal judges nationwide.

Following oral arguments this past week, the JPML issued the MDL transfer order April 3. The panel indicated District Judge Case Rodgers will preside over the litigation in the Northern District of Florida. Judge Rodgers oversaw a similar MDL for Abilify compulsive gambling lawsuits. This MDL reached a global settlement agreement to resolve the litigation earlier this year.

According to the JPML, all parties in the Combat Arms litigation agreed on the establishment of an MDL. However, there was some disagreement over where the JPML should consolidate the litigation. 3M argued the cases should be centralized in Minnesota as its corporate headquarters are located there. But, the panel ultimately decided the Northern District of Florida was the most appropriate venue.

“On the basis of the papers filed and the hearing session held, we find that these actions involve common questions of fact, and that centralization will serve the convenience of the parties and witnesses and promote the just and efficient conduct of this litigation,” the panel wrote. “All actions involve common factual questions arising out of allegations that defendants’ Combat Arms earplugs were defective, causing plaintiffs to develop hearing loss and/or tinnitus. Issues concerning the design, testing, sale, and marketing of the Combat Arms earplugs are common to all actions.”