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Required in America

In the 1970s the Federal Motor Vehicle Safety Standard # 218 went into effect—establishing mandatory safety standards for all motorcycle helmets sold in the United States for street use. Since the Department of Transportation is the agency tasked with administrating the standard, the standard has become known as “DOT” helmet standard.

Given its legal status, the DOT is by far the most common motorcycle helmet standard in America. But how does it stack up against its European counterpart, the ECE 22.05, or the voluntary Snell M2015?

High energy impacts, but a relatively high G threshold.
At first glance, the DOT may not impress. While both Snell and ECE standards fail helmets that transfer more than 275 G’s to your head during an accident, the DOT standard allows for a peak acceleration of 400 G’s—a level that seems, comparatively speaking, quite high.

The DOT standard attempts to reduce impact severity by stipulating that the transfer of G’s can never exceed 200 G’s for more than two milliseconds. Supporters contend that this requirement reduces the actual G threshold to something well below 400 G’s. Critics, on the other hand, have long argued that the standard could be improved with a simpler maximum threshold. DOT has no positional stability test nor chin bar test, which we supplement at the Dome by testing to the Snell positional stability and chin bar tests for our DOT only helmets.

When it comes to actual impact testing, the DOT standard strikes a balance between the Snell and European standards. To wit, DOT requires multiple high-energy impacts on both hemispherical and flat anvils. It also features the same shell penetration test as Snell’s M2015.

The only self-certifying motorcycle standard.
The DOT standard however doesn’t require that helmets pass as many hurdles as either Snell M2015 or ECE 22.05. DOT, for instance, doesn’t require a chin bar test or, surprisingly, a roll-off (positional stability) test—something that is core to most helmet standards.

Finally, detractors of the DOT standard note that the standard does not require third-party certification. Each helmet manufacturer or distributor is responsible for ensuring that their helmet truly meets DOT standards before they apply DOT certification stickers to their helmets.

The Department of Transportation does contract with third party testers who verify that DOT-certified helmets truly meet the national standard. Some argue, however, that this approach could lead manufacturers to pass off non-complying helmets as DOT-certified.

*This chart compares impact energies across standards, per each standard’s required drop heights. For illustration purposes, it assumes a headform weight of 5 kilograms, though some standards actually test a variety of different headform sizes/weights).

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