Whether you step into a puddle of water mixed with petrol while wearing leather boots or you drip petrol onto your boots from the pump nozzle, petrol will stain the leather nearly instantly. Do not attempt to remove petrol from leather boots with water or any water solution. Oil and water do not mix, so the petrol stain will simply spread. Likewise, avoid removal methods involving sandpaper, abrasive sponges or chemical concoctions not specifically made for leather. The trick to removing petrol from leather is to absorb the oil out of the boot gently and repeatedly.
Dab the stained areas of your leather boots with a dry rag or washcloth to remove any surface petrol as soon as possible. Do not scrub the boots' surface or you may push the petrol deeper into the leather.
Sprinkle the stained surface of your leather boots with corn flour. Completely cover the stain, patting the corn flour down gently with your hand.
Leave the boots in a cool, dry spot such as a cupboard, wardrobe or dry basement for eight to 10 hours. Excessively warm locations may disfigure the leather, and excessively moist locations may cause the corn flour to absorb more moisture from the air than from the boots.
Vacuum the corn flour up with a soft brush attachment or use a shoe brush or your hand to gently brush the powder away. Your stain should be noticeably lighter, though it will probably not be fully removed unless the petrol barely splattered your boots. Repeat the steps until the stain is sufficiently removed.
Use baking powder or talcum powder if you do not have any corn flour on hand. Treat your leather boots with a leather protector to help prevent future stains. Watch out for puddles at petrol stations and car parks and try to stand clear of the pump nozzle at petrol stations.
Some petrol stains, because of their age, depth or size, may require a commercial leather cleaning product or the services of a professional leather or shoe repair person.