ASTM Method D-5384
U.S. EPA regulations (Federal Register 40 CFR 266.40 and 279.44) require that used oil to be burned for energy recovery must contain less than 1000 ppm total halogens (4000 is the permissible limit if determined that the halogens are not from a listed hazardous waste - see Clor-D-Tect ® Q40