People ask me all the time when they should get rid of a helmet. My response鈥攖hat 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鈥攊s inevitably met with an eye roll and an explanation of why it isn鈥檛 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 , creators of the first helmet safety standards. Most climbing, snowsport, and cycling helmets are made with expanded polystyrene (EPS) liners, says Zhang. 鈥淓PS is essentially plastic beads with air bubbles packed together very tightly,鈥 she says. Those air bubbles crunch down during impact to cushion your head, and they don鈥檛 rebound. 鈥淓ven if your head hits just a little bit鈥攍ike a fall from one or two feet鈥攖he inside liner is compromised,鈥 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.
鈥淲hen we tell people every three to five years, they just think we鈥檙e trying to make more money,鈥 says Thom Parks, who has overseen testing, standards, and safety at since 1998, including now its in-house testing lab, . But it鈥檚 not about money. When it comes to your noggin, it鈥檚 always better to be safe than sorry. If your helmet is less than five years old and you鈥檙e unsure if it needs replacing, Parks has a list of questions you can ask yourself to determine if it鈥檚 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. 鈥淵ou can do an inspection or send it to the manufacturer, who can do a very good inspection to see if that helmet was damaged,鈥 he says. 鈥淚n good light, check the inside and outside of the helmet, and look for evidence of crushing or cracking.鈥
If there鈥檚 minor crushing, you may not have to replace the helmet. 鈥淚n reality, the next accident probably won鈥檛 hit in the same spot,鈥 Parks says. 鈥淔or the most part, a helmet that鈥檚 crushed a little bit is probably going to work fine in the next accident, but it鈥檚 dangerous for anyone to make that statement, because we don鈥檛 know what that next accident is going to be.鈥
Your safest bet is to call the manufacturer and send it in for the inspection, Parks says. 鈥淭here are very few that would need the helmet for more than a day or two.鈥
#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鈥檙e 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. 鈥淭ypically, you know if the helmet took a good hit, because a good hit to the helmet is a good hit to the head,鈥 Parks says. 鈥淛ust even the sound of the impact or the way your head felt鈥攍ike if you hit hard enough to see stars鈥攃an tell you if the helmet should be replaced.鈥
#3. Has the Helmet Come into Contact with Chemicals?
鈥淭he reason most helmet makers suggest you replace a helmet every three to five years is because we don鈥檛 know what kinds of chemicals and environments its been subjected to,鈥 Parks says.
Case in point: 鈥淩ogaine and DEET are very damaging to helmets,鈥 Parks says. 鈥淓ven some sunscreens will cause a little bit of damage.鈥 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鈥檚 going to see your dome under the helmet anyway) or spraying DEET only below your chin. 鈥淟et the sunscreen sink into your skin before you put that helmet on,鈥 Parks says.
#4. Where Are You Storing It?
Helmets are surprisingly resistant to climate and temperature changes. Parks says Bell has a 鈥渉elmet garden鈥 on the roof of its lab聽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. 鈥淚f you have an electric motor near your helmet, the output will break down plastics,鈥 Parks says. Even though it won鈥檛 do much to EPS, it could degrade the helmet鈥檚 hard plastic shell. 鈥淎nd if you have a water heater in your garage, it is better to not have your helmet right next to that,鈥 he says.