The label "ASTM/SEI certified" has become commonplace in safety helmets over the years, but few riders know what the acronyms stand for, let alone what's required to earn this seal of approval.
The American Society for Testing and Materials (ASTM) is a century-old organization that writes safety standards for everything from artificial playground surfaces to firefighters' suits. The ASTM draws up testing procedures and safety requirements for each item, standards that can then be adopted by individual organizations, such as USA Equestrian.
Once the standards are in place, the Safety Equipment Institute (SEI) ensures that they are followed by manufacturers, who do their own in-house testing or contract the testing out to other laboratories. SEI representatives periodically visit labs to audit procedures, and twice in the first year (and annually thereafter), the organization sends batches of helmets to an independent certified testing lab.
To earn certification, all protective helmets (including bike, hockey and equestrian models) are dropped onto a flat anvil from a height of about six feet, and from several angles and directions. A second anvil test is designed with the particular risks of the sport in mind.
"For equestrian testing, the second anvil has a very sharp corner that the helmet is dropped on," says Dru Malavase, who has served on the ASTM's equestrian protective-headgear committee since 1984. "This is just like the impact the side of a jump or a horse's hoof would have."
Computer sensors measure the shock from the fall that is transferred to the inside of a helmet in terms of gravity force (g).
"The threshold at which the most serious head injuries occur is 300g," says Malavase, "so all helmets must be under that -- and not even the tiniest bit over."
A separate test focuses on the helmet's harness strap to assure that it remains in place during a spill. The helmet is placed on a head form "with realistic human bone structure," explains Malavase, "and then weighted and dropped." The straps must hold the helmet on the head without stretching beyond a certain amount.
All helmets are retested for concussion and retention after being frozen to minus-20 degrees, heated to over 120 degrees and submerged in water overnight. If the helmet still transfers no more than 300g and the strap is still effective, that design earns ASTM/SEI approval.
"With all we put riding helmets through around the barn," says Malavase, "we have to know that they are still going to protect us."
This article originally appeared in the August 1998 issue of EQUUS magazine. To read more about rider safety, pick up the November 2003 issue of EQUUS.