Skip to content

Frequently Asked Questions

Used oil is a resource, not a waste.

Re-refined oil is used motor oil that undergoes an extensive re-refining process removing contaminants.

Used oil can be recycled for re-use in its original application as a lubricant or to a product that may be used as fuel or an energy source.
Re-refineries recover 75% of base lube oil from each litre of used oil and the heavy oil residue which contains the depleted additives can be added to bitumen for use in road-making or used as a heavy fuel oil.
The distillation criterion is important because it denotes the temperature at which a product will be totally evaporated in a boiler or furnace application. It equates to some degree to the heating value of a product, and also gives proxy information about other criteria. A distillation criterion is always set for new fuel and bunker fuel, and so should be set for recycled oil so that customers can make appropriate comparisons.

The 90% distillation figure is an important indicator of quality, especially for the High Grade Fuel Oil, since it signifies that distillation has been performed successfully. It is not as important for the Low Grade Fuel and Mid Grade Fuel Oil, which will include ash and non-combustibles.
The toxicity of PCB’s has led to a regulatory level set by the National Management Plan (1996), and consequent State and Territory regulations which require fuels to be ‘PCB free’ – that is, to contain no more than 2 ppm (2 mg/kg) PCB.

The source of PCBs in recycled oil is likely to be mixing of transformer oil, which is commonly contaminated with PCBs, with the used lubricating oil stream. Since PCBs would not be removed by any of the recycling technologies now in use for production of burner oils, the industry is careful to segregate the two streams, with PCB oils going for destruction rather than reuse. It should be noted that the use of PCBs in transformer oils is being phased out and this source of chlorinated oils should disappear in the near future.
Flash Point is the temperature at which vapour is given off which will ignite when an external flame is applied under standardised conditions. A flash point is defined to minimise fire risk during normal storage and handling.

The flash points of the various grades of oil would normally be similar except for possible presence of petrol fractions taken up by used engine lubricating oil and solvent contamination not removed during re-refining. Flash points of >60oC are considered to offer adequate safety assurance while preserving the flammability desired in burner use.
The gross heating value is the amount of heat produced by the complete combustion of a unit quantity of fuel. The minimum values recommended in the Standards increase slightly as used oil is subjected to more extensive treatment and non-calorific impurities are removed.

Some customers will be prepared to pay more for ‘premium’ product that has higher heating value while merely meeting the other criteria that define the particular grade (primary, secondary or tertiary).