No they don't: hard hats, or safety helmets, have a
'use by date' or a
'working life'.
Section 3 of Australian Standard AS/NZ 1800:1998 details the "Care and Maintenance of Occupational Protective Helmets" and Section 3.4 covers the "Working Life".
The Australian Standard specifies a
3 year replacement date.
Each helmet, when manufactured, has a year and month of manufacture stamped onto the inside of the shell near the peak for easy reading. The arrow in the stamp points to the month and the arrow overlays the arrow. For example, if the arrow points to 9 and the number is 05 - then the helmet was manufactured in September 2005.
If the helmet has been used regularly, it should be replaced after 3 years from the
date of issue. The date of issue should be marked on an additional sticker on the inside of the helmet as the back of the shell. The date of issue may not be the same as the date of manufacture.
The harness/headband has a life of
2 years only and should be replaced at an earlier date.
Problems arise when:
-
The date of issue is not marked on the additional sticker
-
The sticker has lifted off the helmet
If a "sticky" monogram, or sticker, is used (rather than painted/embossed logo) and placed on the helmet at the time of production by the manufacturer, BEWARE, as some of the glues used to the sticky label react with the helmet shell and the hardness of the hat may be compromised.
Where there may be confusion it is best to use the date of manufacture as the benchmard because it is permanently stamped on the inside of the helmet leaving little room for error.
In offices, safety helmets are often issued as part of an
Emergency Evacuation Plan. These helmets are also governed by the 'use by date' and should be inspected regularly.
If a helmet has been stored in direct sunlight or sitting on a shelf exposed to heat (inside a locked car for example), the quality of the helmet will have deteriorated. There are instances of helmets shattering when used after being stored in direct sunlight for extended periods of time.
RECOMMENDATIONS:
-
Workplaces should develop a system to ensure that safety helmets and harnesses are replaced on a regular basis.
-
Employers should ensure that employees are aware of the need to protect safety helmets from sunlight, heat and chemicals.
The above information is based on the NSW Department of Primary Industries Safety Bulletin 'Hard Hat Expiry Date' (March 2006)