According to chemical structure, plasticizers are classified into phthalic acid esters, aliphatic dibasic acid esters, benzoic acid esters, benzoic acid esters, polyol esters, chlorinated hydrocarbons, epoxies, polyesters, etc. Others are also classified by function (internal plasticizer and external plasticizer) and by function. Phthalate esters are the largest category of plasticizers in the amount of Z, mainly including ortho -, meta -, and para - phthalic esters, with more than Z phthalate esters, accounting for more than 80% of the market share of plasticizers. Common phthalates include more than 10 kinds, such as diisooctyl phthalate (DEHP) and dimethyl phthalate (DMP). The "culprit" in the Taiwan plasticizer event is diisooctyl phthalate, or DEHP (trade name DOP), which is also one of the largest amount of phthalates. Of course, in this case, DEHP was illegally added to replace palm oil to save costs, but it was only regarded as an oily substance, not a plasticizer.