Since 2002, temporary bans have been used to control NPS in the United States. The Comprehensive Crime Control Act of 1984, which was signed into law on October 12, 1984, amended section 201 of the Controlled Substances Act (CSA) (21 U.S.C. 811) to give the Attorney General the authority to temporarily place a substance into Schedule I of the CSA for one year without regard to the requirements of 21 U.S.C. 811 (b) if he finds that such action is necessary to avoid imminent hazard to the public safety (see The Controlled Substances Act, 1986, Part B § 811 (h). If proceedings to control a substance are initiated under 21 U.S.C. 811(a)(1), the Attorney General may extent the temporary scheduling up to six months 21 U.S.C. 811 (h)(2).

In 2012, Section 201 of the CSA, 21 U.S.C. 811 was amended and the time for temporary placement of a substance into schedule I of the CSA was extended up to two years and in the case that proceedings to control a substance are initiated under 21 U.S.C. 811(a)(1), the Attorney General may extend the temporary scheduling for up to one year. 21 U.S.C. 811(h)(2) (see Amendment Federal Food, Drug, and Cosmetic Act S.3187). The Attorney General has delegated his authority under 21 U.S.C. 811 to the Administrator of the Drug Enforcement Administration. To make a finding that placing a substance temporarily into Schedule I of the CSA is necessary to avoid an imminent hazard to the public safety, the Administration is required to consider three of the eight factors set forth in section 201 (c) of the CSA (21 U.S.C) 811 (c)). These factors are as follows: the substance's history and current pattern of abuse; and what, if any, risk there is to the public health. 21 U.S.C. 811 (c)(4)-(6). Consideration of these factors include actual abuse, diversion from legitimate channels, and clandestine importation, manufacture, or distribution. 21 U.S.C. 811 (h)(3).

Since 2002, several NPS have been placed under temporary control under Schedule I of the CSA: BZP and TFMPP were placed under temporary control in 2002 (Federal Register: September 20, 2002 [DEA-226F]); 2C-T-7 was also placed under temporary control in 2002 (Federal Register: September 20, 2002 [DEA-225F]). 5-MeO-DIPT was placed under temporary control in 2003 [Docket No. DEA-238F]. In March 2011 five synthetic cannabinoids (JWH-018;JWH-073; JWH-200; CP-47,497 and CP-47,497 C8 homologue) [Docket No. DEA- 345F]. In October 2011, three synthetic cathinones (mephedrone, methylone and MDPV) [Docket No. DEA-357]. In May 2013, other three synthetic cannabinoids (UR-144; 5-fluoro-UR-144, XLR11 and APINACA, AKB48) [Docket No. DEA-373]. In November 2013 three synthetic phenethylamines (25I-NBOMe, 25C-NBOMe, and 25B-NBOMe) [Docket No. DEA-382].

In February 2014, four synthetic cannabinoids (PB-22/QUPIC, 5-fluoro-PB-22/5F-PB-22, AB-FUBINACA and ADB-PINACA) [Docket No. DEA-385]. In March 2014, 10 synthetic cathinones (4-MEC, 4-MePPP, α-PVP, butylone, pentedrone, pentylone, 4-FMC, 3-FMC, naphyrone and α-PBP) [Docket No. DEA-386]. In January 2015, three additional synthetic cannabinoids were placed under temporary control (AB-CHMINACA; AB-PINACA and THJ-2201) [Docket No. DEA-402]. In July 2015, the synthetic opioid, N-(1-phenethylpiperidin-4-yl)-N-phenylacetamide (acetyl fentanyl), and its optical, positional, and geometric isomers, salts and salts of isomers, were included into schedule I pursuant to the temporary scheduling provisions of the Controlled Substances Act [Docket No. DEA-413F].

On 13th November 2015, the DEA extended the temporary schedule I status for three synthetic phenethylamines (25I-NBOMe, 25C-NBOMe, and 25B-NBOMe) into the Controlled Substances Act. This final order will extend the temporary scheduling of these three NPS for one year, or until the permanent scheduling action for these three substances is completed, whichever occurs first [Docket No. DEA-424].

On 27th September 2016, the Administrator of the Drug Enforcement Administration issued a notice of intent to temporarily schedule the synthetic opioid, N-(1-phenethylpiperidin-4-yl)-N-phenylfuran-2-carboxamide (furanyl fentanyl), into schedule I pursuant to the temporary scheduling provisions of the Controlled Substances Act. This action is based on a finding by the Administrator that the placement of this synthetic opioid into schedule I of the Controlled Substances Act is necessary to avoid an imminent hazard to the public safety. Any final order will impose the administrative, civil, and criminal sanctions and regulatory controls applicable to schedule I controlled substances under the Controlled Substances Act on the manufacture, distribution, possession, importation, exportation, research, and conduct of, instructional activities of this synthetic opioid (see here).