What is the DOT motorcycle crash helmet standard?
When you buy a motorcycle crash helmet, you expect it to offer a decent level of protection and work pretty well as a helmet.
Well, much of the reason your expectations are met is probably down to the fact that motorcycle helmets are regulated when they’re put up for sale in the US – meaning they have to meet certain performance standards. If they don’t, the manufacturer/importer are fined and the helmet’s withdrawn from sale.
The name of this process? DOT. Or more specifically the Department of Transport FMVSS No.218 safety compliance testing for motorcycle helmets – FMVSS being the Federal Motor Vehicle Safety Standard.
All of which is a good thing and should mean that if you buy a helmet with a DOT sticker on the back, it meets certain minimum standards for absorbing the shock of an impact; resisting impact penetration and having a retention strap that won’t stretch like a rubber band. Meaning it should protect your head in an accident.
So what is the DOT test?
The way it works is that the National Highways Traffic Safety Administration make a set of standards available to all manufacturers looking to sell helmets in the US. These manufacturers then need to produce helmets that’ll pass the test. If they do, they’re allowed to self-certify that the helmet will pass FMVSS 218 and can put a DOT sticker on the helmet when it goes on sale.
The Office of Vehicle Safety Compliance are then tasked with testing a number of helmet models per year (in 2007 is was around 40) to ensure they comply with FMVSS 218 standards. If the OVSC find a helmet doesn’t pass their test, the helmet is removed from sale and the vendor has to either repair or replace the helmets for consumers at their own cost. They can also face very stiff fines.
The test itself comprises three elements.
First what’s called the impact attenuation test – which means the helmet is subject to impacts against a rounded and flat anvil after the test helmets have been ‘conditioned’ to reflect four different operating environments. That includes humidity, low/med/high temperatures and water immersion – all of which aims to ensure the helmet will still perform in different extremes of riding conditions.
Each helmet is impacted at four sites with two impacts per site. Testers can choose where on the helmet to impact providing it’s above a ‘test line’, approximated below.
Next is a penetration test where a 6lb 10oz pointed striker is dropped from 118 inches onto various parts all round the helmet – again against helmets that have been pre-conditioned to reflect four different operating conditions.
And finally, the retention strap is tested under 50 and 300lbs loads to ensure it doesn’t elongate more than an inch after load.
The only other check that the helmet then undergoes is to ensure that there’s enough peripheral vision allowed by the helmet – that’s a minimum of 105 degrees from center.
If a helmet passes all these tests, it’s then reckoned to be compliant and the manufacturer/importer won’t get their ass kicked (phew!).
You can recognize a self-certified DOT helmet by the DOT sticker on the outside rear of the helmet – although you can buy phony DOT stickers online so a sticker’s not always a guarantee. However, manufacturers are also required to put a label on/inside the helmet stating the manufacturer’s name, model, size, construction materials and month/year of manufacture – and helmets that aren’t produced to meet the FMVSS 218 standard don’t usually have all the correct labeling in place.
If you’re still not sure a helmet is DOT compliant, then you’ll find a few other pointers on the NHTSA official website that offer you some further pointers. And if you want to read LOTS of detail on the compliance testing itself, check out this link for the laboratory test procedure.
The DOT test probably isn’t the last word in ensuring your helmet’s a good one. But neither is it supposed to be – it’s more a way to ensure crash helmets sold as rider protection offer a minimum level of protection.
The next stage is to look towards Snell certified helmets (or SHARP in the UK) who both take compliant helmets (ECE 22-05 approved helmets in the case of SHARP, DOT in the case of Snell) and put them through more rigorous testing procedures to try and ensure they’ll give better real-world accident protection. Read our articles on Snell, SHARP or ECE 22.05 for more information.