Frequently Asked Questions


Everything you might want to know about helmets in general and why Snell certification is important. Read on, download audio-version of the whole set directly here (mp3), or Listen on Google Podcast

What's the latest?

This question requires some background. The first thing to know is that, in most cases, head injury is caused by a sudden stop. The head is sailing along briskly but, in an instant, the head slams to a complete stop against something hard and unyielding. Unless that head is secured inside a good helmet, that sudden stop will send a shock wave through the scalp, skull and brain tissue. There’s almost sure to be a painful bump and swelling, there may be skull fractures, and that shock wave may even propagate through the brain tissue causing bleeds and disruptions and the kinds of permanent injury that are beyond the most modern medical capabilities to repair.

It’s not the fall, it’s the sudden stop that does the damage. Helmets work by making that stop less sudden.

When the helmet shell slams into something hard and unyielding, it stops almost instantly. But the head inside remains in motion a bit longer by crushing the yielding impact liner that lies between the wearer’s head and the helmet’s outer shell. This impact liner is usually made of EPS - expanded polystyrene- the same material often used in disposable packaging material for delicate furnishings and electronics. As the still moving head crushes the EPS impact liner against the inside of the helmet shell, the liner exerts a controlled braking force that slows the head much more gently than if the helmet not been there.

Two questions remain: is the stop still too sudden? That is: is the impact liner’s gentle braking force still too high to prevent injury? And, is the liner thick enough not to run out of crush before the head inside the helmet slows to a stop? There’s only so much room for crush. If the liner runs out of crush room before the head slows to a stop, the still moving head must then stop abruptly. It may not be as severe an impact as if the helmet had not been there, but there still may be injury and, perhaps, severe injury as a result.

The short answer is 'No.' Snell certified motorcycle helmets are also subject to local requirements. Snell Certified helmets sold in the U.S. cannot be any harder than DOT allows and Snell Certified helmets sold in Europe and many other places cannot be any harder than permitted by ECE 22-05.

For a given impact, the softer the liner, the greater the liner crush. If a helmet runs out of crush room in the liner before the head comes to a stop, the head must then stop abruptly. Effectively, the helmet transitions from soft to hard and the head slams into that suddenly hard helmet liner. The helmet liner must be hard enough to slow a test head form to a complete stop before it is completely crushed and still soft enough not to exceed government standard requirements in DOT or ECE 22-05. DOT and ECE call out the test demands including impact speeds, head form configurations and so on and, so long as the helmet performs successfully, it’s legitimate for street motorcycling.

Real world crash impacts can be significantly more severe than those in DOT or ECE testing. If a rider is going to bother wearing a helmet, the best choice is one that will perform at the greatest velocity current helmet technology can reasonably manage. Those are the helmets we look for here at Snell.

The main reason for two Snell standards is that there are two significantly different mandatory helmet standards. DOT requirements apply throughout much of North America while ECE demands apply in Europe and many other parts of the world. However, each of these two falls far short of demanding all the protection current helmet technology can reasonably provide. Snell standards seek to make up this shortfall. M2020D looks for all the protection that might be built into a helmet that would still meet DOT. M2020R looks for all the protection reasonably possible for a helmet which might still meet ECE demands including those currently set forth in ECE’s new ECE 22-06. DOT and ECE 22-06 are sufficiently different that the best response to one is a little different than the best response to the other. If Snell didn’t have to work within these mandatory demands, a single Snell standard would do but, the constraints being what they are, Snell has instead called out test requirements and criteria that allow the best fit between those of the mandatory test minimums and the best helmet we think currently possible.

Snell is an independent, third-party, non-profit helmet standard and testing organization serving public safety interest for over 60 years. Both DOT and ECE are government minimal standards that rely mostly on helmet manufacturers to police themselves. Voluntary Snell Standards are the most stringent for impact protection. After passing certification testing, every Snell helmet model in the retail market is randomly purchased and tested continuously at Snell lab to ensure premium protection. Riders can verify each Snell certified helmet by model and size on the Snell website.

The answer is no. ECE helmets are not required anywhere outside of Europe. In fact, ECE doesn’t even check those ECE labeled helmets sold outside the European Union beyond its jurisdiction. Snell/DOT certified helmets provide better protection and meet legal requirements throughout North America.

All governmental standards represent minimal requirements. Impact testing requirements in the DOT standard have higher criteria than those in ECE 22.05 and 22.06 standards, but DOT has a limited ability to check helmets in the market and allows helmet manufacturers to certify their own helmets. Snell M2020D and M2020R certified helmets remain the most protective helmets available, tested by a non-profit and independent organization.


More questions

A helmet buyer can quickly judge a helmet for style and price. Wearing a helmet for 10 minutes will help choosing a helmet with good size and comfort. But it is much more difficult to determine which helmet provides the most protection. A helmet is a safety equipment. When your skill and experience could not help you avoid a crash, when your helmet is the only thing between your head and a violent collision, it matters which helmet you have on your head. Snell Foundation tests thousands of helmets every year to find out which helmets can provide the best protection through the most current technology and material. Snell Certification points out those helmets that pass our severe tests. The Snell label lets you know that your helmet will perform its most important function: protect your head when all your judgement, skill and luck have failed to keep you from harm.

Snell is experienced. Snell has been setting standards and testing helmets since the late 1950’s.
Snell is independent. By policy, Snell’s directors and staff members take no financial interest or employment with the helmet industry nor do they accept any gifts.
Snell is capable. The Snell laboratory submits to regular audits and has been accredited to ISO laboratory standards since the late 1990’s.
Snell is
more demanding than any of the current national and internationals standards for motorcycle helmets. We look for all the protection a rider might reasonably wear. Since even this level of protection might not be enough, surely no rider ought to wear any less.
Snell certification is more than high standards; it is testing. Helmets are certified only after meeting all test requirements at the Snell lab. Then, samples of certified helmets sold to consumers are bought randomly from retailers for more compliance testing. Snell certified helmets means high impact management and premium head protection.

You may see "Snell" or "Snell Approved" on the outside helmet shell next to the DOT and helmet model name label. In every Snell certified helmet you should find a certification label, often under the comfort padding. Each Snell standard label has a bar code, a different color for various standards, and the year the standard becomes effective. Without the certification label, the helmet is not part of the Snell certification program and does not have the confidence of the Foundation. You can find illustrations of these labels here. Please report any claims or false advertisements to us. Snell updates the list of certified helmets daily

William "Pete" Snell was the "Racer of the Year" when he died needlessly in a 1956 Sports Car Club of America racing event. His then state-of-the-art helmet, made of leather and pressed cardboard paper, didn’t protect him. The following year, in memory of Pete, a number of his friends, colleagues, and fellow racers, including Dr. George Snively, formed the Snell Memorial Foundation, now known as Snell Foundation. Its purpose was to set helmet performance standards to encourage the development and use of truly protective helmets.

Unused helmets stored in good condition do not automatically expire after five years. Replacing helmets every five years is a judgement call based on testing helmets used by the California Highway Patrol by Dr. George Snively. Wear and tear, the simple act of putting on and taking off helmets, damage the comfort pads and energy absorbing foam liner over time. Helmets with worn-out pads are at least one to two sizes larger than helmets in new condition. A poorly fitted helmet makes it more likely that the helmet will shift too much or even come off the head during a crash impact. For these reasons, Snell recommends replacing helmet after five years of normal use.

First, you should try a few helmet models to find one that feels most comfortable but snug all the way around the head. To check if the helmet is too big, you should buckle the strap and try to pull the lower back of the helmet forward and then push the front brow area of the helmet backward to see if the helmet will slip off either way. If it does, the helmet is too large. A new motorcycle helmet should fit very snugly. Most people buy a new motorcycle helmet one size too big. To make sure the helmet is not too small, you should leave the helmet on your head for at least five to ten minutes to see if there is any discomfort. Some helmet models have exchangeable cheek pads for better comfort. Watch this short video for helmet fitting.

DOT and ECE are law of the land for motorcycle helmets sold in the US and in European Union countries. Although government standards are required, they also are the minimal standards. Snell Standards demand the highest premium protection that current technology and materials can offer. Snell Standards are voluntary. Many of the best helmet manufacturers decide to design and make helmets to Snell Standards because many consumers seek out Snell certified helmets.

Snell does not make or sell helmets. Snell only tests helmets and awards certifications to those that pass. Helmet manufacturers and retailers set prices. Snell certified helmets are available in almost every price range. Building consistently protective performance into a helmet does cost money. Other features, such as comfort, fitting, and graphic design, also contribute to helmet price. Good manufacturers focus their spending on quality control, design and development. Snell certification is your best assurance that the manufacturer has made and continues to make this investment in your safety.

The cost of Snell certification is directly paid by the helmet manufacturers. However, Snell is really funded by helmet buyers who look for Snell certification on the helmets they purchase.
For manufacturers, the direct and average cost for Snell certification of a motorcycle helmet is estimated at about $2.00 per helmet. This includes the certification sticker with a unique serial number for tracking, the certification testing fee to determine if the helmet is designed and made to meet Snell Standard and follow-up random sample tests to ensure certified helmets directly purchased in the market continue to meet Snell standards. There are indirect cost for manufacturers seeking Snell certification. They spend more on in-house quality control system and test lab as well as research and development, so that they will not have non-compliance issues with Snell’s random sample testing program and keep up with the updated tougher Snell Standards.

Snell tests helmets for public safety and publishes a certified helmet list to inform the public. Each helmet maker that voluntarily submits helmets to Snell pays the same price for testing service. Manufacturers also pay for the Snell certification label that goes into every certified helmet. Both the certified helmet list and testing fees are posted on this website. Snell spends most of its income on operating the certification and testing programs. There are regular operating cost such as rent and staff, as well as maintenance on its test facility in California, equipment calibration, repair, and replacement, and all the other expenses associated with operating a non-profit business. Every Snell certified helmet sold is a vote of confidence on what we do. As long as there are enough funding for the Snell lab to keep testing and certifying helmets, the public does not have to rely on manufacturer’s advertisement as the only source of product information. As a non-profit organization, any extra funding resources does not go into private or individual pockets. It is used for the Foundation's education program to keep consumers informed and its research program on latest science and technology to make helmet safer.

First, start out with trying on a Snell certified full-face helmet. All Snell certified helmets provide the same level of premium protection for the brain. If for some reason you will not wear a full-face helmet, there are several Snell certified open-face ¾ helmet models that offer the same brain injury prevent capacity as Snell certified full-face helmets. The next step down is DOT full-face helmets and ¾ open face helmets. You should understand that by choosing a DOT helmet, you are giving up 40% to 80% of impact protection comparing with any Snell certified helmets. Snell does not recommend half helmets because those helmets are inadequate for injury prevention.

Imagine yourself in a car crash. Without a seat belt, your body will keep moving until it impacts the windshield or the dashboard. Such impact is the sudden stop that is harmful to the brain. Unlike damaged arms and legs, brain injuries can be life threatening and there is no way to put a seat belt on the brain inside our head. A good helmet acts like a skillful driver applying a braking force, like a few taps on the brake to slow down the car before a full stop, giving your head and brain inside the helmet a little more time to come to a gentler stop. The thickness and density of the foam inside a helmet provides 5 to 6 milliseconds of time for the brain to slow down. The hard shell in motorcycle and auto racing helmets spread the impact to a larger area of the foam, so that the helmet can manage even more severe shock to prevent brain injuries. Together, the hard shell and crushable foam liner give the brain more time and distance to slow down and prevent brain injuries. Watch these videos about how helmet works to prevent brain injury.

Generally the answer is probably not. If your helmet drops to the ground from your hand, off a seat or handle bar of a motorcycle, you do not have to replace it. In general, the real damage comes when the helmet contacts an object with a head inside. However, helmets are one-use items, so treat them with care. Frequent dropping, or spiking a helmet on any hard surfaces may eventually degrade the helmet's performance. Similarly if the helmet falls to the ground at highway speeds unoccupied, damage to the helmet may degrade its protective capability. Snell recommends that if you are participating in an activity that requires helmet use, you should pay attention whenever your head hitting things. Without a thorough inspection by a trained professional, it can be difficult to determine if a helmet has been damaged and its protective capabilities compromised. Some manufacturers may provide this service or direct you to others that can perform these inspections. If you suspect your helmet may be compromised, Snell recommends that you replace it. If the helmet has been involved in an impact while in use, replace it. Even good helmets cannot provide adequate protection the second time.

Unlike sport helmets that are designed to take multiple low impacts, Snell certified helmets are all crash helmets that work well in managing severe impact shock in only one accident. The crushable helmet liner absorbs the impact shock by collapsing itself. Such damaged helmet cannot protect the brain the second time.

Wherever possible, you should try on a helmet for 5 to 10 minutes before buying a helmet to ensure proper fitting and size.

Helmet price is not an indication of protective capacity. Although there are Snell certified helmets in different price range, all Snell certified helmets meet the Snell test requirements. In addition to protective capability, other features on a specific helmet, such as graphic design, unique shell and liner combination for different head size, and improved fitting for different head shape, can add a lot to helmet manufacturing cost. Snell standards don’t consider issues like weight, bulk, ventilation, noise reduction, comfort, style or fit quality. You can tell us about these better than we could ever tell you. Shop carefully; a $150 dollar helmet you won’t wear is no bargain. Please check out the Snell certified helmet list before shopping for helmets and try helmets on your head before purchasing.

All Snell certified helmets go through the toughest tests at the Snell lab. A lot of expensive equipment in the ISO 17025:2017 certified Snell lab is maintained and calibrated for repeatable and reliable testing by experienced Snell test technicians. There are various destructive and non-destructive tests to evaluate helmets, such as visual field clearance, buckle systems, face shield penetration, and many more. The most critical test is the impact test that a helmeted test head form crashes on different impact surfaces. You can see it for yourself by taking an on-line lab tour.

Every helmet on the market is designed to meet the standard label on that helmet. None of the modular helmets sold in the market is designed to meet the Snell Standards. Snell has been inviting helmet makers to submit modular helmets for certification for the past 20 years and have tested quite a few different models and sizes. Snell demands that modular helmets must meet the same testing requirements as full face style helmets. Unfortunately, almost all the prototype modular flip-up helmets tested in the Snell lab have not been able to meet all of the standard requirements consistently. In some cases the complexity of the designs and mechanisms interfere with impact protection. This is sort of like a convertible top car in which a rider may sacrifice some protection to have the feature of a removable top. Please write to your favorite manufacturer to try harder. After all, you are the customer the manufacturer relies on.

Snell recommends the latest Snell Standards to all consumers who need head protection. Each association, racing track, and event establishes unique rules for safety equipment use by its members and participants. Most of these organizers require the use of helmets meeting the current or the immediate previous Snell Standards. For example, the current auto racing helmet standard is SA2015. SA2015 and SA2010 are required now, until SA2020 becomes effective in October 2020. By then, SA2010 helmets may not be allowed any longer.

Snell only certifies helmets as they leave the helmet manufacturing factory. Any additional installation of after-market accessories can invalidate the Snell certification. If you choose to install after-market accessories, make sure it is done properly by knowledgeable and experienced professionals.

The SA standard is designed for competitive auto racing. The M standard is for motorcycling and other motorsports. The K standard is issued to accommodate helmets used in karting. There are two major differences among them:
  • The SA standard requires flammability test while the M and K standards do not.
  • The SA and K standards allow for a narrower visual field than the M standard. This means that some SA and K certified helmets may not be street legal.

First, take the strap to go through both D rings. After pulling the strap through both rings, guide the strap to go back over the first ring and slide it through the second ring. Then tighten the strap down to make sure it is snug to your face. The strap should not be too loose to allow more than two fingers to go through under your chin. Watch this short video for demonstration.

Follow manufacturer’s instructions. Do not place your helmet so that any hard object, such as the motorcycle mirror or handle bar, can damage the inner foam liner of the helmet. Don’t place your helmet close to high heat such as a muffler that could melt the inside of the foam liner. Only use mild soap water to clean the inside pads. Never use any chemical cleaning products for the inside or outside of your helmet. Never repaint your helmet with paints that are not authorized by the manufacturer.

Many enjoyable activities involve head injury risks. Brain injuries can lead to loss of life quality and even life itself. Helmets are proven measures to prevent and reduce such risks effectively. Snell encourages everyone to wear a helmet while bicycling, motorcycling, skating, skiing, horseback riding and auto racing. Snell certified helmets for various activities provide the best head protection available to the public.