The primary difference between a Snell and a Department of Transportation, or DOT, helmet is the degree of impact absorption, according to the Snell Memorial Foundation. DOT standards are government standards for motorcycle helmets set in Federal Motor Vehicle Safety Standard 218 (FMVSS 218). Snell standards are set by a private organization and surpass DOT standards.
The Snell Memorial Foundation, which began in 1957 after the death of Pete “William” Snell, is a non-profit organization that conducts independent reviews beyond DOT standards. Snell explains that it conducts a variety of tests, including impact, positional stability, dynamic retention, chin bar, shell penetration, faceshield penetration and flame resistance.
According to the National Highway Traffic Safety Institute, the Snell standards and a sticker indicate that a helmet meets the federal safety standard.
In addition to motorcycle helmets, Snell states it has safety standards for equestrian sports, bicycling, rollerblading and skateboarding, snowboarding, skiing and karting. Helmets.org states that the U.S. Consumer Product Safety Commission sets standards for bicycle helmets.
Sharp, a UK-based company, states that it has improved testing above Snell to ensure a helmet’s safety. Sharp conducts 32 impact tests over a broader range of speeds and conditions to better represent real world crashes.
DOT helmet certification meets government requirements, but additional certification from Snell, Sharp or the American National Standards Institute all improve a helmet’s crash resistance.