If the poser has stunned you, the answer is a shocker: The used oil (thick black oil) from your bike or car is actually stoking up a multi-crore parallel business that has detrimental effects on the environment and your health. The used vehicle oil is being sold to industries as a replacement for high-priced furnace oil and light diesel oil (LDO). Burning of used motor oil, without subjecting it to reprocessing (where contaminants are removed), increases air pollution levels.

Karnataka State Pollution Control Board (KSPCB) chairman Lakshman told The Times of India: "Around 20,000 to 25,000 barrels of waste and used oil are generated in the state every month, but only 10% of it is received for reprocessing. The rest lands up with the unorganized sector and is used as combustion fuel without being reprocessed. Roadside garages let the used oil into drains and sewers; that is a big worry as this oil can cause great damage to the environment."

In fact, the KSPCB recently did a random check on automobile service stations and found that there was no accountability with regard to used oil.KSPCB's senior environmental engineer A Ramesh said; "Used vehicle oil, which would have lost its additives, should not be reused directly . Used oil is classified as hazardous waste and is governed by the Hazardous and Other Wastes (Management and Transboundary Movement) Rules - 2016 as notified by the Union ministry of environment, forest and climate change.But a majority of service stations are selling the used oil to illegal buyers, who in turn sell it to industries."

Environmentalists maintain that used oil is insoluble and contains toxic chemicals and heavy metals. Used motor oil obtained from a single oil-change process can contaminate around 37 lakh li tres of water when released into the open.

"But the situation is alarming in Karnataka, especially Bengaluru," warned Lakshman. Though there are 36 recycling and refining units in the state, a huge chunk of oil generated by ser vice stations do not reach these units. Used oil is not only sub stituted for furnace oil and LDO in foundries, bitumen based units, lead-smelting units and battery industries on the Kar nataka-Maharashtra border, but is also sent to indus tries as far as Delhi, Haryana and Gujarat.

"Moreover, vehicle owners don't get any discount on their bills, though service stations charge them for oil change and pocket the money obtained from selling the used oil that right fully belongs to the former," Ramesh added.

While the used oil that is drained out from a multi-utility vehicle (MUV) varies between 5 litres and 6 litres during ser vice, the used oil removed from a two-wheeler is 600-900ml.

Given the fact that there are 1.73 crore vehicles in Karnataka (Bengaluru alone has 67 lakh vehicles, including 45.93 lakh two-wheelers and 12.81 lakh four-wheelers), the used oil generated every day adds up to several lakhs of litres.