Hi Matt.

Thanks for the opportunity to ask a question. My question is about helmet life. More often than not it seems that the life of a helmet is determined by when it smashes into something (i.e. a crash, knocking it on a tree limb or dropping it off of a balcony). Should a helmet ever be disposed of after a certain number of years of use?

Do helmet manufacturers need to start putting expiration dates on helmets like bottles of milk? 

LC

Hey LC. Excellent questions. In general, yes: Helmets have an expiration date. That’s because exposure to sunlight, heat, and other elements degrades the foam and other parts of the helmet. Plus, helmets tend to get knocked around with use. You don’t want to mess around with something designed to save your life.

A few years ago, as I prepared to head out for a ride in a particularly buggy region, I sprayed my helmet with Off!. When I removed my helmet at the end of the ride I noticed the clear coat on the shell was blistered from the bug spray. I couldn’t tell if the foam was compromised too, but I didn’t want to find out the hard way—I trashed the helmet. It was a really nice Specialized Ambush with MIPS and ANGI too, so I was super annoyed. But having a functioning brain capable of annoyance is a gift, so I moved on, confident that my new helmet was in proper order.

I forwarded your question to several helmet makers to get their opinion. Most stated that you should replace your helmet every three to five years.

“The reason is due to repeated small impacts (placing in the car, dropping in your house, etc.), along with the constant exposure to the elements as an outdoor product (high heat or UV exposure, deep cold exposure, very arid climates, very humid climates, Being left in the garage through the changing seasons and temperatures, sweat, etc.), the materials that comprise our helmets will degrade over time. We’ve seen that after around three years of this type of regular use and exposure the materials will no longer perform at the high standards we test them to when they are new,” Casey Garrity of Sweet Protection explained.

Essentially, if you have an older helmet that looks haggard and you’re starting to wonder, “How long have I been wearing this thing?” it’s probably definitely time to replace your helmet.

In their response, Ulysse Daessle of Bluegrass and Met’s PR team adds a bit more colour, “As we can’t follow closely the history and the usage of the helmet done by the customer, we precautionarily suggest to replace the helmet after three to five years of use. We arrived to this number because in the statistics of an average use, it’s the time after a big percentage of the products could be subject to hard conditions, crash, marks of use, small hits, being stored in a car, etc. It’s really probable that after three to five years, we match the conditions LC described as ’smashed into something’. We have to advise the customer: A helmet is a safety device and you really need to take care of it and change it in case of doubt. So we take this safety margin and advise to change your helmet after three to five years of use.”

The clock does not start ticking when the helmet rolls off the assembly line, however. If stored in the typical “cool dark place”, the helmet’s usable life doesn’t start until you expose it to the elements. “The lifespan starts when the product is first in use which is why you don’t see expiration dates on our helmets. As manufactures, we can’t determine when the product will be put on its first ride but sunlight, sweat, bug juice, and more effects the lifespan of the product,” wrote Sam Foos of Bontrager Marketing.

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Daessle, of Met’s PR and marketing department, agreed with Foos on this point, “We’ve tested helmets that has been stored in our warehouse and never used, and they were performing as intended even after a long period of time.”

A dissenting opinion on the three-to-five year replacement schedule came from Brad Waldron, co-founder of Kali Protectives, “It really comes down to how the helmet has been cared for. Kept in good condition and not stored in the sun and extreme conditions, the helmet will last a long time. Way longer than what the manufacturers like to tell you. I’m comfortable saying 10 years when treated well.”

Waldron backed up his pronouncement by stating that “most” helmet manufactures add UV inhibitors to the foam—limiting degradation from sun exposure—and by pointing to a study by MEA Forensic.

In that study, MEA and collaborators subjected 671 used helmets—some were up to 26 years old—in good condition to the standard CPSC drop test. Only four of the helmets did not pass. “We observed little or no support for age-related deterioration of bicycle helmet impact performance that would justify replacing a helmet in good condition every 2–10 years as recommended by some bicycle helmet manufacturers,” the report concluded.

Naturally, there are some caveats, the biggest being, “Within the limitations of our sample and test conditions” as well as, “Other helmet features that may change with age were not evaluated in this study.” But the study does seem to say that the foam—which does most of the force mitigation in an impact—in a well-cared-for helmet helmet is good for much longer than three to five years.

But the difference between a properly cared for and an improperly cared for helmet in a crash might literally be life and death. Three to five years is more than enough time for a rider to accidentally drop a helmet a few times, or leave it on the backseat of a car for a few days, or mistakenly use a harsh solvent to clean it. And let’s be real: If the helmet brands, or I, give bad or even improperly stated advice we can wind up subjected to crushing lawsuits.

Plus, as Kali’s Walton pointed out, “There has been a lot of good research on new materials, foam densities, multi-density, low-G impacts, rotational injuries, and more. The latest technologies can only be found in newer helmets. You can’t retrofit the old ones.”

Is there an element of “cover your ass” in the three to five year helmet replacement recommendations? You betcha. But most of all, we all want you to have the best possible chances of surviving a crash. And it is my belief—and I think many of people working at helmet brands feel similarly—that a “fresher” helmet with the latest tech is more likely to protect better in an impact than an old helmet that might have been dropped a few times, or exposed to something that degraded its protective capabilities.

Essentially, if you have an older helmet that looks haggard and you’re starting to wonder, “How long have I been wearing this thing?” it’s probably definitely time to replace your helmet.

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