There are also many electric vehicles. All forms of fossil fuel energy produce heat and combustion products. In the case of electricity, the environmental impact is transferred to the area of production. Additional weight also adds to the amount of aircraft fuel consumed. This type of waste is not toxic.
Special wastes vary from paint strippers to cleaning solvents and acids.
All require careful handling and disposal. Similar to glycol used in car radiators and has a relatively high oxygen demand when it breaks down in waste water. These contain fire fighting foam which has a high oxygen demand when it breaks down in water systems. The waste water contains oils and greases which have a high oxygen demand when they break down. Aircraft tanks are pumped to special vehicles and transported to approved drainage points connected to foul sewers.