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New Zealand UV sun strength and its affect on PPE

New Zealand UV sun strength and its affect on PPE

Richard Tregoweth - Thursday, November 22, 2012

Back in 2008 IRATA (Industrial Rope Access Trade Association) issued a Warning about the affects of ultra-violet light on personal fall protection equipment.

According to IRATA "There is irrefutable evidence to suggest exposure to ultra-violet light (UV) weakens many man-made fibres".

These textiles include polyamide, polyester, polyethylene, polypropylene and aramid.

A large proportion of PPE sold in NZ is sourced out of Europe, manufactured to stringent safety standards.

"Although European Standards for personal fall protection equipment incorporate safety factors, they do not address explicitly the potential for degradation by UV and abrasion during use of the product, relying instead on its strength when new."

The fact EN testing does not specifically address UV degradation is the logic behind the Safety Warning from IRATA.

And… if IRATA recognize UV degradation as a major issue in the Northern Hemisphere we can multiply the problem by two here in New Zealand!

Why you ask? Answer; the sun strength in the Southern Hemisphere is far stronger than our Northern neighbors.

There are three scientific reasons for this:

  • there is less ozone in New Zealand to block UV rays.
  • the earth's orbit takes us closer to the sun during the southern summer than during the northern summer.
  • there is less pollution in the southern hemisphere to filter and subdue UV rays.

The sun's strength is measured by the UV index.

The highest possible UV index at sea-level is about 20. This can occur at midday in equatorial regions. Any reading higher than 10 is extreme in terms of UV degradation.

By way of comparison the UV Index in the Mediterranean in high-summer reaches 9 or 10.

Here in New Zealand the summer index often exceeds 12. In the far North, 14 is reached - you can check the New Zealand regional UV index daily on the NIWA website.

So… UV degradation in New Zealand is not restricted to man made textiles used in the manufacture of PPE; hardware will also degrade if left in full sun for any period - helmets are particularly prone to UV degradation - see image below.

Please make sure you check all your PPE regularly.

IRATA UV degradation warning notice

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