Safety Helmets Explained: EN 397 vs EN 12492, Bump Caps and Electrical Helmets
Most safety helmets look alike, but they are built for different jobs. An industrial helmet, a climbing helmet and a bump cap are tested in completely different ways, and the wrong one can fail exactly when it is needed, or even cause an injury of its own.
The short answer: EN 397 for construction sites and factories with falling objects. EN 12492 (or a helmet with both ratings) for working at height and rope access, where the helmet must stay on in a fall. EN 812 bump caps only for low spaces with no falling objects. EN 50365 when working near live electricity.
The four standards side by side
| Standard | Type | Protects against | Chin strap |
|---|---|---|---|
| EN 397 | Industrial safety helmet | Falling objects, penetration | Releases under load, so it cannot strangle |
| EN 12492 | Climbing / height helmet | Falling objects, side and front impacts | Holds firm, so the helmet stays on in a fall |
| EN 812 | Bump cap | Bumping the head on fixed objects only | Not required |
| EN 50365 | Electrical insulating helmet | Live electricity up to 1,000 V AC (Class 0) | As EN 397 |
EN 397: the site helmet
This is the standard helmet for construction, factories, warehouses and maintenance. It is tested for impact from above and for penetration by a sharp falling object. Its chin strap, if fitted, must release under load, so a worker caught by the helmet cannot be strangled.
EN 397 helmets can carry extra markings for tested options:
- -20 °C or -30 °C: tested at very low temperature.
- +150 °C: tested at very high temperature.
- 440 V AC: brief accidental contact with live conductors. This is not protection for electrical work.
- LD: lateral deformation, tested for crushing from the side.
- MM: molten metal splash, for foundries and welding.
EN 12492: working at height
When a worker on a harness falls, the helmet must stay on their head as they swing into a structure. EN 12492 helmets have a strong chin strap that holds, and they are tested for impacts from the front, sides and back, not just the top. Many height-work helmets carry both EN 397 and EN 12492. See the working at height guide.
EN 812: bump caps
A bump cap looks like a baseball cap with a hard shell inside. It protects against knocking your head on pipes, shelving or vehicle undersides. It is not a safety helmet and gives no protection against falling objects. Never use one where a helmet is required.
Electrical work
A standard EN 397 helmet is not electrical protection. For work near live electricity, choose a helmet tested to EN 50365 Class 0 (up to 1,000 V AC), with no ventilation holes. Vented helmets are cooler, but the holes let current through. See the electrical hazards guide.
American helmets use ANSI/ISEA Z89.1 instead: Type I protects the top of the head and Type II the top and sides. Class E is tested to 20,000 V, Class G to 2,200 V, and Class C gives no electrical protection.
Vented or non-vented?
Vents make a big difference to comfort in the Egyptian summer, and a helmet that is comfortable stays on. Choose vented for general site work, and non-vented for electrical work and where molten metal or chemical splashes could get in.
How long does a helmet last?
- Check the date moulded inside the shell, usually as a small clock symbol. Follow the manufacturer's replacement period, which is often a few years from manufacture for plastic helmets.
- Sun and heat age plastic faster. Helmets left on car dashboards or in the sun go brittle sooner. Store them in the shade.
- Replace after any serious impact, even if no damage shows.
- Replace if cracked, faded, chalky or deformed, or if the harness inside is worn.
- Do not paint, drill or put solvent-based stickers on the shell. They can weaken it.
Accessories that fit the system
Many helmets take clip-on earmuffs, visors and lamps in their side slots. Buy accessories made for that helmet model, so the helmet keeps its rating. See our guides to hearing protection and eye and face protection.
Questions buyers ask us
Do helmet colours mean anything?
There is no international colour standard. Many sites use their own code, such as white for engineers and supervisors and yellow or orange for workers. Follow your site's rules.
Can I wear a cap under my helmet?
Only a thin liner or cap designed for that helmet. A thick cap or scarf stops the harness fitting properly and reduces protection.
What is the difference between a ratchet and a pin-lock harness?
Both adjust the fit. A ratchet adjusts with a knob while the helmet is on, which is faster and fits more precisely, so it is better for long shifts.
Buying for a team
Order helmets by job: EN 397 for the general site, EN 12492 for anyone working at height, and EN 50365 for electricians. Add chin straps where workers bend, climb or work in wind. Send the list through For Companies and we will quote within 24 working hours, with bulk prices from 20 pieces.