A rider securing his helmet strap before hopping onto his motorcycle. - 13ching13/ShutterstockWho makes the best motorcycle helmets might be up for debate. However, what's not debatable is that every helmet made since October 3, 1988, has been subject to a national safety guideline known as Standard No. 218 (49 CFR 571.218). This Code of Federal Regulations establishes the minimum mandatory performance and construction requirements for motorcycle helmets designed and sold in the United States. One of those is that all helmets have a permanent, legible "DOT" label that displays some very specific information.DOT-compliant helmets sold in the United States are required to have a visible label fixed on the back that contains the manufacturer's name (or the brand), the model designation, and the words "DOT," "FMVSS No. 218," and "CERTIFIED." Helmets made before May 13, 2013, may have labels that just read "DOT." Oddly, the National Highway Traffic Safety Administration (NHTSA), which is part of the U.S. Department of Transportation, doesn't actually approve helmets — or any other motor vehicle equipment for that matter — itself. Instead, they depend on manufacturers to self-certify their own helmets, believing companies will do the right thing to keep their customers safe.While most testing is performed randomly, if the NHTSA receives tips or complaints from riders about a helmet or manufacturer, it will conduct tests to ensure standards are being met. If the helmet fails, the NHTSA can issue a recall and force the manufacturer to remove the helmet from stores until the problem is fixed and the helmet is certified properly. These testing results are made public and can be searched on the NHTSA's Compliance Test Report Database.AdvertisementAdvertisementRead more: 18 Motorcycle Hand Signals Everyone On The Road Should Know AboutHow to identify a DOT-certified helmetGloved finger pointing to a DOT certification label on the back of a motorcycle helmet. - CAN-AM OFF-ROAD/YouTubeMotorcycle helmets save lives, but only when properly designed and certified to do so. Even though every helmet — no matter the style or type (of which there are many) – sold in the U.S. must meet federal standards and carry the DOT certification label on the back, some retailers still sell "novelty helmets." DOT safety standards make it illegal for anything to extend more than two-tenths of an inch off the surface of a helmet. In other words, all those cool-looking helmets with mohawks, spikes, unicorn horns, and ears are illegal in many states and will not protect you if you get into an accident. Some (but not all) German Army and skullcap helmets are also unsafe.Furthermore, fake DOT labels can be bought to circumvent Standard No. 218. In many states, wearing a helmet without an official DOT sticker could earn you a ticket. Penalties and fines vary by state, so be sure to check the local laws where you live. Certification labels from SNELL (a private non-profit) or ANSI (the American National Standards Institute) might also be found, but most states only require the DOT sticker.When purchasing a reliable, DOT-certified helmet, be sure it weighs around three pounds. Anything lighter than that isn't legitimate and is likely unsafe. Thickness of the inner liner — made from stiff expanded polystyrene foam that looks like Styrofoam — must be at least three-quarters of an inch thick. If a helmet has buzzwords claiming it's the "thinnest" or "lightest," it usually indicates it's not safe or compliant. Lastly, helmets must have sturdy chin straps with solid rivets, and those with plastic buckles are almost certainly non-compliant.AdvertisementAdvertisementWant the latest in tech and auto trends? Subscribe to our free newsletter for the latest headlines, expert guides, and how-to tips, one email at a time. You can also add us as a preferred search source on Google.Read the original article on SlashGear.