CAN is not acid forming fertiliser, because it contains

CAN is not acid forming fertilizer, because it contains Calcium.
Calcium ammonium nitrate is hygroscopic. Its dissolution in water is endothermic, leading to its use in some instant cold packs.
Fertilizer grade CAN contain roughly 8% calcium and 21 - 27% nitrogen. CAN is preferred for use on acid soils, as it acidifies the soil, it lowers the pH of the soil, but does not acidify it because of the presence of calcium.