Thinking of environmental issues in the workshop, used oil is more or less the first substance that comes to mind. It can pollute drinking water by a factor of thousand in terms of volume and has been used
throughout the car history. Nowadays we do not only find it in engines and gearboxes, but in numerous auxiliary aggregates, e.g., hydraulic power steering. Also hydraulic shock-absorbers can not get by without it, even though it
does not need to be changed during their lifespan.
How it works
One must distinguish between, used oil of known and of unknown origin. Known means that one has drained the oil personally, or at least, that the job was done in a workshop. Only in this case you can be sure that
no flammable liquids, e.g., petrol, are contained in the oil. It can then be stored in special containers and premises in the
dangerous-materials class III, (55 - 100°C ) where it can later be disposed of. Also, one can be sure that it was not mixed with automatic gearbox oil. This oil would contain PCB and could possibly not be re-
processed. All this is uncertain if the oil was simply delivered in a canister, e.g., when purchasing new oil. This oil, therefore, is stored in different containers and falls under the dangerous-materials class I (up to 21°
C). The cost of recycling this oil again or to dispose of it is far higher.
Engine oils, manual gearbox oils and used oil filters should be stored separately from other waste and be collected by especially equipped companies to be reprocessed. ATF oils from automatic gearboxes can
contain PCB and must be disposed of as a hazardous waste. Lubricating oils (like diesel oil) belong in the dangerous-materials class AIII, and must therefore, also be stored in special containers and premises.