The short answer
There’s no legal expiration date stamped on a motorcycle helmet. But most manufacturers and Snell recommend replacing a helmet around 5 years from its manufacture date — not from when you bought it — based on materials aging and the EPS foam liner compressing and degrading with use, heat, and UV exposure over time. (Lid & Visor, HelmetsAdvisor.com)
That said, this is genuinely a point of some debate in the riding community — the certification itself (DOT FMVSS 218 or ECE 22.06) doesn’t expire; it documents what the helmet tested at when new, and some riders and sources argue EPS foam stabilizes after its first couple of years and doesn’t meaningfully degrade further in normal storage. (ALLR.io, r/motorcycles discussion)
The practical takeaway: treat the 5-year guidance as the manufacturer’s conservative baseline, not a hard safety cliff — but combine it with the checks below rather than relying on a single number either way.
Find your helmet’s actual age first
Look for a manufacture date stamped or printed under the comfort liner, on the chin strap, or molded directly into the EPS foam. This is the date that matters for the 5-year guidance — not your purchase date, since helmets can sit on a shelf before being sold.
Replace immediately regardless of age if:
- You’ve crashed in it or dropped it hard enough to impact the shell. EPS foam is designed to crush once to absorb energy — it doesn’t spring back, even if the damage isn’t visible from outside.
- You see cracks, dents, or separation between the shell and liner.
- The fit has changed — a helmet that’s gotten noticeably looser over time means the liner has compressed from sweat, oils, and repeated use, regardless of the calendar.
- The retention strap or buckle hardware shows wear that compromises a secure fit.
Replace on the standard interval if:
- It’s been 5+ years since manufacture and you ride regularly, especially in hot climates or with significant UV exposure (both accelerate shell and foam degradation).
- You can’t verify the helmet’s full history (bought used, inherited, or storage conditions unknown).
Why this matters even with “no visible damage”
The core risk isn’t cosmetic — it’s that EPS foam’s energy-absorbing capacity can diminish from heat cycling, UV exposure, and the chemical breakdown of adhesives and foam over years, in ways you can’t see by looking at the outside of the shell. A helmet that looks fine can still have measurably reduced protection in a real impact. This is why “it still looks new” isn’t the same as “it will still perform like new.”
From the field
I go with the manufacturer’s recommended 5-year rule, counted from the date of manufacture — not the purchase date. So my advice is simple: find that actual date stamped on your helmet and go by that, not by how long you’ve owned it or how it looks.