There are six major requirements a helmet, for this use, needs to surpass to be certified:
1. Field of vision.
Making sure the helmet design does not interfere with the user’s field of vision
2. Extent of coverage
Making sure the helmet covers all necessary parts of the head
3. Shock absorbing capacity
The most important is the shock absorbing capacity of the helmet. This is tested in a specialized instrument where the helmet is dropped with the speed of 2,5m/s onto a solid metal anvil with a 4 kg metal head inside. Inside the metal head there’s an accelerometer that measures the forces within the impact. The helmets are tested in four conditions:
High temperatures (+35ºC)
Low temperature (0ºC)
After artificial aging,
After the helmet has been submerged for 4 hours.
Each helmet is tested on several areas (crown, side, rear & front). The peak acceleration must not exceed 250G for any of the impacts.
4. Retention system performance
This test covers the strength of the retention system (webbing), as well as its effectiveness, i.e. the webbings ability to keep the helmet securely positioned on the head.
After being submerged for at least 4 hours, the helmet must float to the surface.
After all these tests the helmet should not show any damage that would cause any additional damage to the wearer.