London -- THE UK's Health and Safety Executive (HSE) has issued a safety alert after a coldstore ceiling gave way, causing two workers to fall to the floor. One of the men died from his injuries.
The store was constructed in the 1970s, using insulation panels made from a sandwich of steel sheets bonded to polyurethane foam. These were bolted to a metal support frame, with engineering grade plastic bolts. HSE said the manufacturer of the panels and bolts is unknown, but points out that "the design is believed to have been common and there are likely to be many of these stores still in use."
The HSE want duty-holders with structures containing insulation panels that are suspended in a similar manner, to:
• Ensure that access to these panels is prevented until their condition is established; and
• Carefully examine the fixing / support systems from underneath for signs of deterioration.
An HSE investigation after the accident showed that the bolts had consistently failed where the thread entered the metal nut which secured them to the supporting frame. Tests identified fatigue and corrosion (due to oxidation and exposure to chlorine) as the main cause of deterioration of the bolts, said the report.
HSE said because the bolts which had failed either dropped down slightly but remained within the panels; or were flush, no obvious signs of failure were apparent.
The HSE reminds duty-holders that:
· Ceilings and roofs should be presumed to be fragile until it is proved that they are not.
· Environmental conditions may cause deterioration of ceilings, roof claddings or their supports, making them incapable of taking a persons weight.
· Panels should not be used as a working platform unless it has been confirmed by a competent person that both the panels and their supports have been specifically designated for that purpose and are suitable.
· Guidance on loading capacities should always be sought from the manufacturer/supplier if possible
· Where frequent access is required then independently supported walkways should be installed, or boards used to spread loading for other prolonged work activities. Again, guidance from manufacturers, suppliers and designers should be followed