People ask me all the time when they should get rid of a helmet. My response—that you should replace your helmet every time you hit your head while wearing it, and at least every five years if you go crash-free—is inevitably met with an eye roll and an explanation of why it isn’t realistic for them to replace helmets that often. Helmets, after all, are expensive.
They are, I respond, but a good one is an essential not worth skimping on. My answer is informed by a conversation I had with Hong Zhang, director of education for the California-based Snell Foundation, creators of the first helmet safety standards. Most climbing, snowsport, and cycling helmets are made with expanded polystyrene (EPS) liners, says Zhang. “EPS is essentially plastic beads with air bubbles packed together very tightly,” she says. Those air bubbles crunch down during impact to cushion your head, and they don’t rebound. “Even if your head hits just a little bit—like a fall from one or two feet—the inside liner is compromised,” Zhang says. And should you never end up taking a dinger, the Snell Foundation says you should still change your helmet every five years just to be safe.
“When we tell people every three to five years, they just think we’re trying to make more money,” says Thom Parks, who has overseen testing, standards, and safety at Bell Sports since 1998, including now its in-house testing lab, the Dome. But it’s not about money. When it comes to your noggin, it’s always better to be safe than sorry. If your helmet is less than five years old and you’re unsure if it needs replacing, Parks has a list of questions you can ask yourself to determine if it’s time to retire your lid.
#1. How Does the Helmet Look?
If and how hard you hit your head is going to make a big difference in whether your helmet has been seriously damaged. Parks suggests starting your decision with a thorough inspection. “You can do an inspection or send it to the manufacturer, who can do a very good inspection to see if that helmet was damaged,” he says. “In good light, check the inside and outside of the helmet, and look for evidence of crushing or cracking.”
If there’s minor crushing, you may not have to replace the helmet. “In reality, the next accident probably won’t hit in the same spot,” Parks says. “For the most part, a helmet that’s crushed a little bit is probably going to work fine in the next accident, but it’s dangerous for anyone to make that statement, because we don’t know what that next accident is going to be.”
Your safest bet is to call the manufacturer and send it in for the inspection, Parks says. “There are very few that would need the helmet for more than a day or two.”
#2. How Does Your Head Feel?
Even though Parks does not suggest getting rid of a helmet after every fall, you definitely should replace it if the helmet took a solid hit. If you rag doll while skiing pow, you’re going to do less damage to your helmet than if you face-plant on a patch of ice.
So how can you know the difference between a minor hit and a serious one? Check in with your head. “Typically, you know if the helmet took a good hit, because a good hit to the helmet is a good hit to the head,” Parks says. “Just even the sound of the impact or the way your head felt—like if you hit hard enough to see stars—can tell you if the helmet should be replaced.”
#3. Has the Helmet Come into Contact with Chemicals?
“The reason most helmet makers suggest you replace a helmet every three to five years is because we don’t know what kinds of chemicals and environments its been subjected to,” Parks says.
Case in point: “Rogaine and DEET are very damaging to helmets,” Parks says. “Even some sunscreens will cause a little bit of damage.” As a rule of thumb, try to keep chemicals off your helmet. There are plenty of workarounds, like holding off on the Rogaine (no one’s going to see your dome under the helmet anyway) or spraying DEET only below your chin. “Let the sunscreen sink into your skin before you put that helmet on,” Parks says.
#4. Where Are You Storing It?
Helmets are surprisingly resistant to climate and temperature changes. Parks says Bell has a “helmet garden” on the roof of its lab in Scotts Valley, California, leaving them in the elements for as many as ten to 15 years. Some still test well after living on asphalt that fluctuates between 100 degrees in summer and below freezing in winter.
But if you store helmets in places like the garage or basement, watch where you put them. “If you have an electric motor near your helmet, the output will break down plastics,” Parks says. Even though it won’t do much to EPS, it could degrade the helmet’s hard plastic shell. “And if you have a water heater in your garage, it is better to not have your helmet right next to that,” he says.