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Bicycle Helmet Safety Institute

The Helmet Update by Email

Volume 23, #2 - May 12, 2005

Previous Issues

Australian Study Compares
Snell and Australian Standards

Summary: An Australian study compared the performance of helmets meeting their standard and the Snell B-95 standard and found them similar, but clearly favored their own standard.

Australia's Transport Safety Bureau commissioned a study by Human Impact Engineering of New South Wales to determine if it was reasonable to use the Snell B-95 standard interchangeably with Australia's own AS/NZS 2063:1996 standard. We were alerted by freelancer Charles Pekow that it is now posted on the Web.

The report grudgingly concludes that the Snell requirements "have the potential to produce a slightly more protective helmet." But the authors were obviously trying hard to discredit the Snell standard throughout the report.

For impact testing, the Snell helmets passed all the AUS/NZ standard tests. In fact, all but one of the helmets met both standards on the flat anvil. That one helmet was marked as meeting the AUS/NZ standard, but investigation showed that it was not actually certified to the standard. That would be a criminal offense in the US and would mean a CPSC-forced recall, but in Australia recalls can only be ordered by the courts, and they have only had one, in 1998. The report cites our 8 recalls as evidence that the US system must be flawed. In fact, it devotes considerable space to detailing all of the CPSC helmet recalls in an effort to show that Australia's "batch release" test system is better. They are probably correct.

On the curbstone and hemispherical anvils the study concluded that the Snell helmets outperformed the AUS/NZ helmets. Three of the five AUS/NZ helmets failed both Snell tests. One Snell helmet was marginal. There is no curbstone or hemi anvil required by the AUS/NZ standard.

Retention (stability) testing was similar. All of the helmets passed all of the AUS tests, a steady pull. But 2 AUS/NZ helmets and 2 Snell helmets failed a modified version of the Snell tests, a dynamic yank more like that of an actual crash, that is apparently more severe. In this case the Aussies impact tested the helmets first, whereas Snell and all other bike helmet standards test the strap first. We are surprised that any of the helmets passed the Snell yank under those conditions. The text mentions broken tri-glides and broken strap anchors on those helmets. The authors conclude that Snell helmets have a consistency problem, and it must be due to the inadequacy of the US standards for quality control. They may be right, but that tends to overshadow the main conclusion from the test results, which is that the Snell helmets passed all of the AUS/NZ tests, and are clearly equivalent to the Australian standard helmets. That includes one from Helmets R Us that sells in the US to non-profits for $4.95. And the Snell helmets did not fail the Snell standard, they failed a different standard developed by the authors.

The Australian standard has one unique test, for load distribution. It tries to measure how evenly an impact is spread over the wearer's skull. All of the helmets passed. The Snell helmets were slightly better. This is not too surprising, since the liner foam density was about the same for every helmet but the Bell Stryker, which was much harder but still passed easily. We would like to see that test in our CPSC and ASTM bicycle helmet standards, but not if it just issues blanket passes to the helmets with stiffer liners.

We will not quibble with the Aussies' preference for their own standard. We have always thought that it probably has advantages in better quality control. But we don't think the testing showed that an AUS/NZ helmet provides better protection than a Snell helmet, and it clearly did not show that Snell helmets do not meet the Snell standard.

The study covers 48 pages. It has a lot of very interesting information and is a "must read" for anyone actively involved with helmet standards.

This page was updated or partially revised on: March 27, 2015.
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