DOT Motorcycle Helmets

If you legally ride a bike on road in US you must be aware of DOT motorcycle helmets. The Department of Transportation (DOT) issued the latest revision of the standard in May 2013. This is the FMVSS 218 and it stands for Federal Motor Vehicle Safety Standard No 218.

How does this work

In US the National Highway Safety Administration (NHTSA) is the authority enforcing the DOT certification but does not test helmets coming out on the market. Instead each manufacturer must test and self-certify their helmets and at that point they can attach the DOT sticker. The NHTSA though will randomly check the compliance with the standard by requesting from the manufacturers samples of their product which will be subsequently sent to independent laboratory for testing. Because the penalties for not meeting the minimum requirement are rather hefty, each manufacturer should ensure their product meet the criteria. 

DOT motorcycle helmets - certification

There are four basic criteria that helmets are rated on:

Impact - the shock absorbing ability. The tests measure the acceleration of the headform inside the helmet when it's dropped from a fixed height onto a flat and spherical surface. The maximum allowance peak acceleration for this standard is 400G where G is the acceleration value due to gravity.

Penetration - the capacity to withstand a blow from a sharp object (dropping it from a fixed height) before that object penetrates through the shell to inside of the helmet. 

Retention - the capability of the chin strap locking mechanism to stay fastened under impact without stretching or braking. This is carried out in room temperature tensile test where load is applied from 22.7 kg (50 lb) and hold for 30 seconds and then increased to 136 kg (300 lb) and hold for 2 minutes. The stretch is measured from the fixed point on the retention strap to the appex of the helmet.

Peripheral Vision - a minimum of 105° of side vision for the helmet mid-line.

All helmets must meet the minimum requirement in these four criteria to pass to DOT certification. In order to make the counterfeit labelling of the non-compliant DOT label more difficult, the label must now include:

Model No and Name


FMVSS No.218


More information on the DOT motorcycle helmets and the FMVSS 218 standard can be found in

Snell helmet rating

The Snell Memorial Foundation is a non profit organization that goes beyond the governmental standards and so your helmet does not have to be certified by Snell to be road legal. Although it is not mandatory it may be required if you want to use your helmet in some competition activities. 

Snell helmet rating is distinguished by helmet manufacturers and they are themselves seeking Snell certification. In order for them to certify they submit the finish product samples (from 5 to 7 complete helmets for each model) to be tested using standardised tests. If it passes, the helmet become certified under the standard (currently M2015) and the manufacturer can label the helmet with the Snell sticker.  

No further design modifications are allowed and any structural modifications would invalidate the certification. Snell keep a sample of a certified helmet in archives for future inspection. In addition random checks on product are carried out to verify continued compliance.

Read more on Snell helmet rating tests.

European helmets

The Economic Commission for Europe, part 22.05 is a basic standard that almost all of European countries comply with (47 out of 51).

In European system, unlike in the US, there is a requirement for every new motorcycle helmet product to be tested prior to the commencement of sale. Generally a batch of ~50 samples for helmets and visors are required to be submitted to approved (by government) laboratories to verify their compliance with the ECE 22.05 standard.

ECE 22.05 vs. DOT motorcycle helmets

Although, the criteria and tests are very similar between the US and European standard, there are some differences.

Firstly, the ECE 22.05 can certify the modular helmets with or without chin bar tests. These are distinguished by:

  • ECE 22.05J if the helmet does not have the lower face cover,
  • ECE 22.05P for protective lower face cover and
  • ECE 22.05NP for non-protective lower face cover.

The DOT motorcycle helmets do not require chin bar testing.

Also, in the impact test mentioned for DOT motorcycle helmets, the maximum allowable peak acceleration at the head form in ECE 22.05 is 275G against the 400G in US.

ECE 22.05 includes performance for the visor where in US this is covered in a separate standard not covered by DOT.

Other differences include rigidity test in ECE 22.05. The load is progressively applied onto the shell when deformation is measured. On the other hand ECE 22.05 does not test for penetration resistance.

Reed more on other motorcycle helmet safety schemes in Europe.

For the complete list of the helmet safety standards around the world click here.

Fitting your helmet

Remember that all of the above safety standards will only apply to a helmet that is properly fitted to your head. Here not only the size matters but the shape of your head. So make sure you've red the section on how to check the fit before you purchase a helmet. 

Return to motorcycle sport touring Home Page