Industrial or climbing type, and why the strap differs
An industrial safety helmet is designed around a falling object. The shell is shaped to deflect the impact and the harness absorbs it, and the chinstrap is deliberately weak: it is required to release at a low force so that a snagged strap cannot strangle the wearer.
A helmet for work at height is built to the opposite requirement. It has to stay on during a fall, so its retention system is strong and does not release, and it adds protection against impacts to the sides, front and rear rather than the crown alone. That is why these look like climbing helmets, because they are tested to a similar idea.
The practical consequence is that a hard hat is the wrong helmet for anyone working at height or likely to fall, and a climbing type helmet is the wrong one where a strap could snag on machinery. Choose from the actual hazard rather than from what is in the store, and check the standard marked inside the shell rather than a listing description.
| Hazard | Helmet type | Retention |
|---|---|---|
| Objects falling from above | Industrial hard hat | Releases under load to avoid strangulation |
| Working at height, risk of a fall | Climbing type helmet | Strong strap that stays fastened |
| Live electrical work | Non-vented, insulating helmet | As required by the electrical standard |
| Forestry and clearing | Helmet with visor and ear defenders | Combined system |
Vented shells, and where they are not allowed
Vents make a helmet considerably more comfortable in heat, and they do it by putting holes in the shell. For general construction that is a straightforward comfort gain worth having.
For electrical work it is not. A helmet intended to protect against contact with live parts has to be an unbroken insulating shell, so it is never vented, and that is a hard requirement rather than a preference. A vented helmet on an electrical job is the wrong equipment however comfortable it is.
Integrated systems are worth considering where the job needs more than a shell. Helmets that accept a visor and ear defenders on the same mounting keep everything on one head fitting rather than three, which in practice is the difference between the eye and ear protection being worn and being in a van.
Harness adjustment and how the helmet actually works
The shell does not touch the head. The harness inside holds it a set distance away, and that gap is the crumple zone: an impact deforms the shell and the harness stretches, and the energy goes into both rather than into the skull. A helmet worn on the back of the head, or with the harness slackened until it sits low, has given up most of that clearance.
Adjust the harness so it is firm without pressure points, sitting level rather than tipped back. A six point harness spreads load better than a four point one and is more comfortable over a long day.
Never modify the shell. Drilling it for accessories, painting it or applying solvent based stickers all attack the plastic, and a shell that has been crazed by solvent can fail at a fraction of the impact it was tested for. Use accessories designed to clip into the existing slots.
Age, sunlight and when to bin it
Helmet shells are usually polyethylene or ABS, and ultraviolet light degrades both. A helmet left on a dashboard or worn outdoors every day ages faster than one kept in a locker, and the degradation is invisible until the plastic becomes brittle.
Manufacturers mould a date of manufacture into the shell, usually as a clock face with an arrow to the year, and they state a service life from that date and from first use. Those figures are the manufacturer instruction rather than a suggestion, and a helmet past them should be replaced regardless of appearance.
Replace immediately after any significant impact, even where the shell looks undamaged, because the energy has been absorbed by deformation you cannot see. The same applies to a helmet that has been dropped a long way onto a hard surface. A helmet is cheap next to what it protects.
