A helmet is DOT approved when it passes the FMVSS 218 safety standard testing set by the United States Department of Transportation. These safety standards involve a series of tests that evaluate the helmet’s impact absorption, retention system, shell integrity, and resistance to penetration.

DOT: The U.S. Department of Transportation establishes the legal federal standard for motorcycle helmets used on public roads and property in the United States. Instead of "approving" helmets, the DOT mandates that helmet manufacturers certify each model sold in the US to meet the DOT standard. The current federal standard is FMVSS 218.

DOT Helmet Standard: This stands for “Department of Transportation,” (not “doin’ our thang”) but the standard is FMVSS 218, the Federal Motor Vehicle Safety Standard #218, Motorcycle Helmets, and it is applicable to helmets sold in the U.S. for on-road use.