The first thing you probably look for when buying a helmet is a seal of approval from either or both the ANSI Z90.4 standard or the Snell Memorial Foundation standard. But how much protection do these two labels really give you?
According to a newly released study conducted at the Biomechanics Laboratory at Wayne State University in Detroit, which put ANSI-and Snell-approved helmets through a series of rigorous tests, a lot.
“The study confirms that the two standards are very valid when it comes to reducing the risk of head injury,” says Jack Thrush, chief of the health surveillance section for the Michigan Department of Public Health in Lansing, which commissioned the study through a grant from the Centers for Disease Control.
It also shows that a Snell-approved helmet, which must survive a more rigorous testing procedure, is not necessarily safer than one approved by ANSI.
The study, which was run by Biomechanics Laboratory Director Voigt R. Hodgson, PhD, evaluated 10 different soft and hard shell helmets: LT’s 500 and 700; Bell’s Brava, Streetrider and Quest; the Giro Prolight; ProTec Mirage; Brancale XP5; ProAction Youth and Zephyr models. Each helmet underwent drop impact tests and chin strap and buckle retention tests similar to those required by both ANSI and Snell. The helmets that rated the safest in the drop test were the LT 500 and 700 and the Bell Streetrider, according to Thrush.
The third part of the study, a skid test, which crashed helmets into a concrete s mounted at various angles, sheds new light on the safety of a hard shell helmet versus soft. The test shows that in general, soft shell helmets have a tendency to “stick” more to the pavement, thus increasing the risk of neck injury. On the other hand, in some cases, the hard helmet proved more likely to cause a facial injury. A skid test is not part of the ANSI or Snell testing.
The skid test also investigated the use of a face shield that would make a helmet even safer. When a clear chin- bearing hockey face shield was attached to the helmet, the chances of both facial and head/neck injuries were found to be reduced.
The data further suggests that if such a shield were attached to a chin cup instead of the traditional under-the-chin strap, the helmet might stay on the head better upon impact. A second study has been launched to investigate these preliminary findings.
While the distinctions between ANSI and Snell standards are minor, it’s still important for any safety-savvy consumer to know the difference when selecting a helmet.
The Snell Memorial Foundation, in St. James, New York, is a private organization that tests helmets in its own laboratories. After a helmet has received Snell certification, the foundation continues to spot check the quality of helmets to ensure that manufacturers haven’t gotten lazy.
The American National Standards Institute (ANSI), in New York City, relies on a committee of industry experts to draw up its helmet safety standard. The testing works on the honor system: Manufacturers independently test their helmets in private or outside labs according to ANSI requirements. If they are satisfied that their product passes, they’re free to call themselves ANSI-approved.
How, therefore, can an ANSI approval have any credibility, you may ask? From eagle-eyed competitors who are only too happy to knock an undeserving rival helmet off its ANSI pedestal, says Channing L. Ewing, MD, who is both the director of research and development of the Snell Memorial Foundation and chairman of the ANSI committee.
“If a company makes an inferior helmet, the competition will go out and test the helmet and inform us if it fails. Companies police each other.”
ANSI and Snell standards are almost identical in their requirements. They both put helmets through temperature, retention and drop impact tests. The only significant difference is that Snell requires a helmet to survive a two-meter drop test instead of the ANSI-okayed one-meter drop.
Even if a helmet is doubly blessed by both ANSI and Snell, don’t be lulled into thinking that you’re invulnerable. “There’s no helmet that can protect your head from all conceivable accidents that could occur,” says Ewing.
And if you do crash, you’ll have to trash your helmet. Helmets absorb the shock by self-destroying on impact, says Edward B. Becker, chief engineer at Snell. “They’re good for one accident, and that’s it.”
(When shopping for a helmet, check out a company’s helmet-replacement policy. For example, Giro will provide you with a new helmet if you crash within a year of purchase.)
However, if your helmet takes multiple beatings during a crash, that’s another matter. The latest safety feature on the market: a structural reinforcement, such as a nylon webbing throughout the helmet, that holds it together after an impact in case there is a second one. Most of the leading models contain this potentially life-saving feature.