This document specifies the requirements, test methods, inspection rules, marking and accompanying documents, packaging, transportation and storage of hexamethyldisiloxane (silyl ether). This document is applicable to waste liquids produced by the pharmaceutical industry from the synthesis of β-lactams (including penicillins, cephalosporins, and penems), antiviral, antifungal, macrolide, and quinolone pharmaceuticals as raw materials. The recovered hexamethyldisiloxane (silicone ether) obtained through pretreatment, distillation and other processes is used in pharmaceutical and chemical production.