A system of Temporary Class Drug Orders on NPS was introduced in September 2011 by the Police Reform and Social Responsibility Act 2011 that amended the Misuse of Drugs Act 1971, introducing Section 151, Schedule 17. Substances placed under temporary control are subject to the Misuse of Drugs (Safe Custody) Regulations 1973 and to the provisions of the Misuse of Drugs Regulations 2001 as if they were specified as controlled drugs to which Schedule 1 to the Misuse of Drugs Regulations 2001 apply. Temporary CDO allow to control NPS for up to 12 months following initial assessment by experts while they review full range of harms. Methoxetamine was placed under temporary control in April 2012 (The Misuse of Drugs Act 1971 (Temporary Class Drug) Order 2012 No. 980), and permanently controlled in February 2013; 25I-NBOMe and other related substances, as well as 5- and 6-APB and other related substances including 5- and 6-IT were placed under temporary control in June 2013 (see Temporary Class Drug Order No.1294 of 2013). In April 2015, 3,4-DCMP; ethylphenydate; IPP; HDMP-28 and propylphenidate were placed under temporary control (see Temporary Class Drug Order No. 1027 of 2015). In June 2015, methylphenidate related materials (3,4-DCMP; 4-Methylmethylphenidate; Ethylnaphthidate; Ethylphenidate; Isopropylphenidate (IPP or IPPD); Methylnaphthidate (HDMP-28); Propylphenidate) were placed under temporary control (see Temporary Class Drug Order No. 1396 of 2015 (No. 2) (effective on 27th June 2015).     

On 23rd November 2015, methiopropamine (MPA) was placed under temporary control under the Misuse of Drugs Act 1971 (see Temporary Class Drug Order No. 1929 of 2015 (No. 3) effective 27th November 2015).[http://www.legislation.gov.uk/uksi/2015/1929/made].