I know someone who insists on using new, unused motor oil to burn garden waste (in a garden area). Somehow, I'm pretty sure this can be bad for the garden and/or people's health who eat the stuff grown in the garden.
Can you please tell me what, if anything, is wrong with this (besides risk of burns and fire spreading)?
Also, can you tell me healthy alternatives that I can suggest that would work just as well? (If unused motor oil indeed makes the ashes unhealthy for the garden, I mean.)