A new website shares everything from helmet materials to standards and testing protocols.

The researchers and engineers behind Giro and Bell’s in-house test lab, The Dome, recently launched HelmetFacts.com. It’s a website where athletes who need to protect their noggins (ahem, triathletes) can find info on everything from helmet materials to standards and testing protocols. Wondering what that cert on your brain bucket means? Allow The Dome team to clarify.

There are dozens of helmet standards across the spectrum of action sports. Different types of helmets help to protect you from different types of impacts. A bicycle crash, for instance, is entirely different than a snowboarding spill. It follows then that bicycle and snowboard helmets should offer relevant levels of protection and live up to relevant standards. Simple.

Here’s where it gets complex. Different countries and organizations also have different safety standards for the same kinds of helmets. There are, for example, 10 different bicycle helmet standards alone.

What do they guarantee? Helmet safety standards dictate everything—from how much of your head the helmet covers to what kinds of labels cover the helmet’s own packaging. But when most people think about helmet standards, they want to know just one thing: How big of a hit can this helmet take before I get hurt? They’re interested in the impact standards.

Helmets help to protect your brain by reducing the amount of energy transferred to your brain during a crash or fall. That energy or force is generally measured in gravitational force or G’s. Experience a force greater than 300 G’s and you’re considered likely to suffer significant head trauma or death. That’s why most helmet standards today require that your helmet transmit no more than 300 G’s to your brain during an impact.

Below, we’ve outlined four of the most important standards for cyclists.

Since March 10, 1999, all bicycle helmets sold in the United States have been required to pass the CPSC helmet standard. Prior to that point, several popular helmet standards (ANSI, ASTM and Snell) floated about, each with substantially different testing regimens. In the United States, helmet manufacturers could choose to meet any, all, or none of those standards.

All of this proved confusing to consumers. Congress passed legislation in 1994 (the Children’s Bicycle Helmet Safety Act), calling for all cycling helmets to meet a single, national standard. Other cycling helmet standards still exist, but now U.S. consumers are guaranteed a common performance threshold with any bike helmet purchased in the United States. CPSC is also accepted in Canada, China, Taiwan, Japan and Brazil. CPSC subjects helmets to slightly greater impacts than both EN-1078 and AS/NZ standards.

Read more on CPSC

EN-1078 / The European Cycling Standard
Created in 1997, the EN-1078 standard was approved in 2012 by the European Committee for Standardization (or “CEN”) for all cycling, skateboarding and roller skating helmets sold in 32 European nations. In other words, EN-1078 is a commonly recognized standard.

EN-1078 permits lighter, thinner helmets than some of the other standards because it subjects helmets to impacts from lower heights than either Snell or CPSC. It’s not as simple as that, though, as EN-1078 does require a lower test line than Snell and CPSC, which may require that the helmet provide slightly more coverage. [The test line is a line drawn around the helmet, below which the helmet is not tested.] Helmets that transmit more than 250 G’s to the headform during impact testing fail EN-1078. The other standards mentioned here allow for up to 300 G’s.

Read more on EN-1078

ASTM F1952 / The Downhill Mountain Biking Standard
This downhill mountain biking helmet standard features greater impact energies and drop heights on the hemi and curbstone anvils than the CPSC or the Snell B-95 standard. [Part of testing requires weighted helmets get dropped from a prescribed height above a steel anvil onto the anvil.] This standard also features a lower test line on the sides and back of the helmet than most other bike helmet standards. While chin bars are not required to pass this test, if a helmet does feature a chin bar, the bar must pass a deflection test as well.

Read more on ASTM F1952

Snell B-95 subjects helmets to harder hits from greater heights than the CPSC and EN-1078 standards. Snell B-95 also features a slightly lower test line than the CPSC standard, requiring protection over a greater area of the helmet.

While this standard has been in existence longer than other cycling helmet standards profiled here, relatively few helmets meet Snell’s 1995 “B-95” standard. This is generally true for at least two reasons: (1) B-95 is a completely voluntary standard and (2) Helmets that pass B95 are generally bulkier and less attractive.

Read more on SNELL B-95

Want to know more about how the testing actually works? Check out this article on Helmetfacts.com.