DOT is the Federal Government’s Department of Transportation (DOT). DOT sets minimum standards that all helmets sold for motorcycling on public streets must meet. The standard is Federal Motor Vehicle Safety Standard 218 (FMVSS 218) and is known commonly as the DOT standard.

The Snell Memorial Foundation is a private not-for-profit organization that sets voluntary standards for motorcycle helmets, bicycle helmets and auto racing helmets, as well as other kinds of protective headgear. Snell standards are the world’s toughest and demand quite a bit more protective capability in helmets than anybody else on the planet.

Both organizations have rigid procedures for testing:

Impact - the shock-absorbing capacity of the helmet.

Penetration – the helmet’s ability to withstand a blow from a sharp object.

Retention – the chin strap’s ability to stay fastened without breaking or stretching.

Peripheral vision – the helmet must provide a minimum side vision of 105 degrees to each side. Most people’s usable peripheral vision is only about 90 degrees to each side.