The Bureau of Alcohol, Tobacco, Firearms and Explosives has tried to ensure “solvent traps” are known as silencers, which are regulated nationally and banned in some states, USA Today reports. Solvent traps are marketed forcatching excess cleaning fluid but can sometimes be used as silencers on firearms. A warning to all federal firearms licensees makes clear that the test of what’s legal isn’t what a device is called but how it can be used. Solvent traps, it said, are classified under the statutes that include “any device for silencing, muffling or diminishing the report of a portable firearm.” Proponents of the devices say they help protect hearing and reduce recoil and muzzle rise, which leads to more accurate shooting. Gun control activists fear silencers make gunshots harder to hear or see, which diminishes the effectiveness of law enforcement and community gunshot detection systems, such as ShotSpotter.
ATF spokeswoman Kristina Mastropasqua said solvent trap devices that function as silencers must be registered by the manufacturer or importer, not individual buyers. In recent years, hobbyists with machining skills have circumvented long wait times for registration of traditional silencer purchases under the National Firearm Act’s “Form 4” by registering their homemade devices under a different process, known as a “Form 1.” Solvent traps no longer qualify for Form 1 registration. Nationwide, Americans purchased and paid the $200 fee to register more than 2.6 million silencers, according to the ATF. They’re legal in 42 states but restricted in California, Delaware, Hawaii, Illinois, Massachusetts, New Jersey, New York, Rhode Island and Washington, D.C. Though they are rare, crimes have been committed with silencers.