Where might you find them?

Glassware under a vacuum, which poses a risk of flying glass:

  • Cathode ray tubes (e.g. TVs, monitors, oscilloscopes).
  • Thermionic valves / vacuum tubes (e.g. radio sets, amplifiers, rectifiers).

Vessels containing gases or liquids at greater than atmospheric pressure:

  • Aerosol cans (flammable propellant gases).
  • Gas cylinder bottles, valves, regulators and pipework (e.g. diving apparatus, laboratory / medical gases).
  • Hydraulic systems (e.g. lifting equipment, vehicles, aircraft).
  • Working steam boilers.
  • Fire extinguishers.
  • Heavily deteriorated tinned food where the can is bulging.

Primed mechanisms:

  • Firearms.
  • Clockwork devices.
  • Compressed springs.

Gravity can also contribute to a hazard – for instance, heavy suspended objects.