Used Oil

How does used oil damage the environment?

Used oil is a potent cocktail of chemicals. These include:

• degraded base oil chemicals
  
• heavy metals including barium, chromium and zinc
  
• wear metals from the engine
  
• residual and degraded oil additives
  
• combustion by-products such as polycyclic aromatic hydrocarbon (PAH)

All of these are potentially harmful to the environment and human health (Clancey, 1999), especially PAH. The various types of PAH can be very dangerous to human health. Some have been identified as having the potential to cause cancers or genetic mutations (Rose Foundation).

Oil decomposes very slowly and the main impact is when Used Oil gets into water. Just 1 litre of oil can contaminate 1 million litres of drinking water (MfE, 1995). Oil forms a film on the surface of rivers and lakes which can reduce the level of oxygen in the water, making it difficult for fish to breathe. It can also coat plants and animals that come into contact with it. In Canterbury large quantities of water are taken from rivers and groundwater for use as drinking water or for irrigation. Oil contamination can make the water unfit for these purposes.† Used Oil dumped on soil can be taken up into plants from the soil and enter the food chain, or could leach into groundwater and affect human health where a groundwater supply is used for drinking. Oil dumped in landfills can also leach into groundwater affecting drinking water supplies.

Toxic gases and metallic dust particles are produced during low temperature combustion of used oil and the high concentration of heavy metals can be damaging to human health if they are emitted from the exhaust stack of uncontrolled burners and furnaces. The resulting ash concentrates heavy metals and must be properly disposed of as a hazardous waste. Only industrial burners that reach very high temperatures with long retention times should be used to burn Used Oil.

You now know why used oil needs to be managed so that it does not end up in the environment. If you are changing oil in your car, boat, lawnmower or any other equipment at home, then you need to dispose of the Used Oil appropriately.

Do's and Don'ts for DIY Home Oil Changers

It is important that oil used or stored in your home is managed carefully.

Do's:

• Get yourself an Oil Drain Pan from your local car parts or oil retailer. An Oil Drain Pan is a container specially designed for draining old motor oil from cars. It saves spills, is clean and easy to use.
  
• If you spill oil, stop it from entering drains by absorbing it with sand or sawdust. Never hose it down a drain.
  
• Pour the used oil into a clean, empty container with a tight lid (e.g., the plastic container the clean oil was supplied in).
  
• Store oil on an impermeable surface such as concrete, and store away from drains. Make sure any oil stored around your home is labelled correctly.
  
• Find out where your nearest used oil collection facility is.
  
• Drop off your used oil next time you are heading that way.

Don'ts:

• Don't pour it down the drain or into the gutter. Many drains are connected directly to a river or stream and pollution will occur, and even small amount can cause serious environmental problems.
• Don't mix used oil with other materials, such as paint or solvents
• Don't throw it in the rubbish
• Don't bury it
• Don't leave it lying around indefinitely
• Don't burn it

Council contacts for Used Oil facilities and information

Note:

All services are free for domestic users (20 litres maximum per drop-off) except in Mackenzie and Kaikoura districts.