HSE SAFETY ALERT:FAILURE OF FROZEN FOOD STORE CEILING

Oxidation and exposure to chlorine cause bolt fatigue and corrosion failure

A Safety Alert has been issued by HSE after two men fell to the floor of a frozen food store when insulation panels separated from the steelwork, which supported the ceiling. One of the men died from his injuries.

The store was constructed in the 1970s and the panels consisted of a sandwich of steel sheets bonded to polyurethane foam. These were bolted to a metal support frame, with engineering grade plastic bolts. 

HSE investigation has revealed the bolts failed where the thread entered the metal nut which secured them into the supporting frame. Fatigue and corrosion (due to oxidation and exposure to chlorine) are the main reasons for deterioration of the bolts. There were no obvious signs of failure.

Summary of action required

HSE reminds dutyholders (see alert for full details) that:

  • ceilings and roofs should be presumed to be fragile until proved otherwise;
  • environmental conditions may cause deterioration of structures making them incapable of taking a persons weight;
  • panels should not be used as a working platform unless confirmed by a competent person as safe to use for the purpose;
  • seek guidance on loading capacities from the manufacturer/supplier if possible; and
  • where frequent access is required independently supported walkways should be installed or boards used to spread loading. 

HSE advices dutyholders with structures containing insulation panels suspended in a similar manner, to:

  • prevent access to these panels until their condition is established;
  • examine the fixing / support systems from underneath for signs of deterioration; and
  • if repairs are required, seek the advice of designers and manufacturers.

This article was posted on 9th November 2010 in ALL LATEST NEWS, FRAGILE MATERIALS, STRUCTURAL SAFETY.
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