Mass. Gen. Laws ch. 94C, § 31
For the purposes of establishing criminal penalties for violation of a provision of this chapter, there are established the following five classes of controlled substances:
(a) Unless specifically excepted or unless listed in another schedule, any of the following opiates, including their isomers, esters, ethers, salts, and salts of isomers, esters and ethers, whenever the existence of such isomers, esters, ethers and salts is possible within the specific chemical designation:
(b) Unless specifically excepted or unless listed in another schedule, any of the following opium derivatives, their salts, isomers, and salts of isomers whenever the existence of such salts, isomers, and salts of isomers is possible within the specific chemical designation:
(c) Unless specifically excepted or unless listed in another schedule, any material, compound, mixture or preparation that contains any quantity of the following substances including its salts, isomers and salts of isomers whenever the existence of such salts, isomers and salts of isomers is possible within the specific chemical designations:
(3) Ketamine.
[Paragraph (d) of Class A applicable as provided by 2018, 69, Sec. 237.]
CLASS A