Helmets are dime a dozen. But do all of them comply with DOT standards? Many do. With the way government has handled this requirement, it is mandatory for helmets to be DOT qualified to be used on the road. And justly so, because DOT lays down some threshold safety standards that will give you a gambling chance in a road accident. DOT levels the ground with motorcycle accident figures by enforcing these rules for helmet manufacturers. It should be one of the prime considerations while buying a lid. DOT certified helmets have proved their mettle against most conceivable threats that emerge out of your love for riding motorcycles.
To understand why you need DOT, you must first understand what it is. You will see the benefits in-situ.
What is DOT?
DOT is short for Department Of Transport which issues the FMVSS 218 standard (Federal Motor Safety Standard No. 218). This standard elaborately explains the bare-minimum safety requirements that a helmet should satisfy for on-road use. The National Highway Traffic Safety Administration (NHTSA) sees that makers follow these guidelines and confirm to them.
NHTSA has a maverick method to eliminate unnecessary bureaucracy from the certification process. Manufacturers do not have to send sample helmets to them prior to producing. Rather, they must test the helmets themselves. If they find that all demands are met, they can affix the authorized DOT sticker themselves to claim compliance with FMVSS 218. NHTSA acquires random sample of these helmets and sends them to an independent testing lab for checking against their terms. If they don’t meet the standard, NHTSA can levy huge fines on the manufacturer.
What do they test?
FMVSS 218 conducts the following tests on DOT motorcycle helmets:
This DOT yardstick measures the acceleration of a mannequin head inside the helmet when it is dumped from a pre-determined height onto a flat anvil. As per the DOT standard:
- Peak acceleration must not exceed 400g (g =Constant 9.8m/s2)
- Accelerations more than 200g should not exceed cumulative duration of 2 milliseconds
- Accelerations more than 150g should not exceed cumulative duration of 4 milliseconds
- This test is to ensure that impact from crash is managed and dispelled effectively through the DOT helmet.
This test checks how steadfastly the DOT helmet sits on the wearer’s head in case of an accident. One of the characteristics of a good helmet is that it doesn’t get yanked off from your head easily. A load is applied to the retention system of the helmet and checked that it doesn’t move off the headform. The adjustable portion of retention system can move up till 1 inch.
This test checks sturdiness of the DOT helmet against a concentrated impact. A penetration striker is dropped vertically from a specified distance in a guided free fall on the outer surface of the helmet. Two such blows are applied 3 inches apart. The striker must not engage deep enough to reach the inner area of the helmet
Each helmet must carry permanent and clear labels with the following information:
- Manufacturer’s name
- Model number or name
- Month and year of manufacturing
- The symbol of DOT as allowed by NHTSA in a contrasting color
Peripheral vision clearance of at least 105 degree is required from the middle plane of the DOT certified helmet to give the motorcycle rider clear visibility on both sides for oncoming vehicles.
The DOT helmet is checked for projections inside. There must not be anything jutting out of the inner surface as it could form a pressure point during an incident. Projections for essential accessories are allowed on the outer surface subject to 5mm height from the surface of the DOT helmet.
As is evident from the tests, FMVSS 218 standards inspect for all aberrations that can reduce helmet performance in case of a mishap. It examines how well the DOT helmet can dissimilate the pressure from a sudden blow. It checks whether the DOT helmet hangs on for dear life on your head when pulled hard. And it checks how much damage a sharp object like shrapnel or metal rod can do if it comes in vertical contact with the lid. It could pierce through the DOT helmet but it must not make contact with your noggin. Finally, it enforces that all critical information is duly printed on the helmet in a legible format. This helps the buyer ascertain all important features of the helmet she or he is buying. This label card will make counterfeiting the DOT helmets a difficult exercise.
DOT certification covers a lot of bases when it comes to helmet safety. But there are other such standards like ECE and Snell. ECE is issued by European Union. It is similar to DOT and accepted in 47 counties. Snell is a much more demanding certification that is revised every 5 years. This standard is compulsory for many motocross events and off-track racing.