Formic acid is available from chemical supply companies. Home hobbyists use formic acid in tanning or bee-keeping. Formic acid can also be purchased online through chemical supply websites.
Oxalic acid is used as rust and stain cleaner and can be purchased from hardware stores.
Safety Note
Concentrated formic and sulphuric acids are corrosive liquids. They should be kept secured in glass or polyethylene containers (plastic soft drink/ soda bottles are not suitable). When using sulphuric acid, rubber gloves should be worn and eye-protecting goggles and a face-splash protector are also essential. Spills of acids onto the skin should be washed off immediately with copious amounts of water. If either of these acids gets in the eyes, wash the eyes continuously for several minutes and then seek medical assistance.
Table 6.3 CO concentration with time using COGen in a vehicle