EN 12492 was written for mountaineers but is now the industry standard helmet for rope access, rescue and work at height. Two things set it apart from EN 397: impact protection from the front, back and sides as well as the crown, and a chin strap that is deliberately designed not to release.
Key differences from EN 397
| Requirement | EN 397 | EN 12492 |
|---|---|---|
| Crown impact | 49 J, ≤5 kN | ≈49 J, ≤10 kN |
| Front, side and rear impact | Not required | Required, 25 J |
| Chin strap | Releases at 150–250 N | Holds ≥50 N, slippage ≤25 mm |
The strap difference is deliberate: on a construction site a snagged helmet is a strangulation risk, so the strap must break away; in a fall from height losing the helmet is more dangerous than keeping it, so the strap must hold.
Many modern helmets are certified to both standards using a switchable retention system — check the label before using one helmet for both kinds of work.