HHSRS Hazard 27 - Explosions

Hazard 27 - Explosions

This hazard covers the threat from the blast of an explosion, from debris generated by the blast, and from the partial or total collapse of a building as the result of an explosion.

A study for the Building Research Establishment (BRE) between 1985 and 1991 showed that the most frequent causes of explosions were mains gas (42%) and stored gas (17%). Water vapour explosions accounted for 5%, and fire for 4%, of the total recorded explosions.

The most likely causes are defective installation or design, and defects from inadequate maintenance.

Vulnerable Group: All ages

Defects & Justifications

• Unauthorised gas supply - the supply of gas from a non-authorised supplier.
• Siting of gas tanks - inappropriate siting of LPG containers or tanks.
• Gas installations - defects to the gas installation (pressure regulators, meters and pipework).
• Gas appliances - defects to the gas appliances.
• Maintenance defects - lack of evidence of regular testing and servicing of the gas installation and/or appliances.
• Ventilation - lack of appropriate means of ventilation, taking account of the type of gas used.
• Gas storage - inadequate or defective storage equipment for other than mains gas.
• Hot water storage tank - tank of greater than 3 gallons (15 litres) connected directly to the mains water supply.
• Vented hot water system - inadequately sized and/or blocked vent to system.
• Unvented hot water system - lack of or defective non self-resetting thermal cut-out and/or temperature relief valve to unvented system.

Index of HHSRS Hazards