Safety Helmet Service Life: When Should It Be Replaced?

A helmet cannot be used indefinitely simply because it has taken no impact. The shell material ages over time, and UV light and heat reduce its strength. The replacement decision should rest on records, not on visible damage.

Find the production date

Every helmet carries a production stamp inside the shell: a clock symbol with the year in the centre and month markers around it. Service life is counted not from that date but from the date the helmet was first put into use, so the date of receipt into stores and of issue to the worker must also be recorded.

Typical life by material

Polyethylene (HDPE) shells are generally usable for 2–3 years from first use, ABS shells for 3–4 years, and glass-fibre reinforced shells for longer. The period stated in the manufacturer's manual always takes precedence. The suspension (headband, sweatband) wears faster than the shell and is usually replaced every 12 months.

Cases requiring replacement before the term ends

If a helmet has taken a single serious impact it is withdrawn from use even with no visible damage; the energy is absorbed by the shell and the structure is weakened. Cracks, networks of scratches, blistering or colour fading, a crackling sound when flexed, and a matt, chalky surface texture are all signs of ageing. Paint, thinner, adhesives and label solvents weaken the shell chemically.

Records and inspection

Numbering helmets and keeping an issue register, and documenting periodic checks on a form every six months, provides the record-keeping order inspections require. Helmets that reach the end of their service life are not returned to stores; they are made unusable and disposed of.

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