Disposal of hazardous substances

Lesson Progress:

Hazardous substances can contaminate land, drains, sewers, rivers and the air.

They should never be mixed with general (non-hazardous) waste, or poured down drains or sinks, onto the ground, or buried, burnt or fly tipped.

Your site or employer should have a procedure to dispose of hazardous waste, including empty or part-used containers.

Highly flammable liquids

Highly flammable liquids (HFLs), such as thinners, solvents, petrol and adhesives, can be easily ignited, catch fire and burn fiercely.

If you have to use HFLs you must make sure of the following.

  • Check there are no naked flames or other sources of ignition nearby.
  • Only take the amount you need for your immediate needs.
  • Always follow the storage procedures.
  • Have the correct fire extinguisher at hand and make sure you are trained to use it.
If a fire extinguisher is needed for hot-work activities it must be one specific for the work activity and the workplace. It should be issued or approved by the person authorising the hot work and you should be trained to use it. Fire extinguishers should not be taken from fire points to cover hot works, no matter how close the fire point is or how short the hot work will be.

Liquefied petroleum gas

Liquefied petroleum gas (LPG) is a form of highly flammable gases held under high pressure to liquefy them. They will readily evaporate if released from the pressure vessel (cylinder). LPG is heavier than air so will sink into excavations, basements, drains and so on.

LPG store

LPG cylinders must be stored upright in a well-ventilated area and in a secure cage. There are separate regulations covering the safe carriage of LPG cylinders in vehicles.

LPG has a distinctive smell. If you think there

  • Others are warned to evacuate the area.
  • The following is carried out, only if it is safe to do so.
    • Turn the cylinder supply valve off.
    • Open doors and windows.
    • Remove any source of ignition. Do not allow the switching (on or off) of electrical apparatus.
  • It is reported immediately.
Gas from a leaking LPG cylinder can expand to 250 times the cylinder’s volume. It can catch fire at some distance from the original leak and flash (burn) back to the source of the leak.