But in 2015 the DEA began targeting previously unscheduled FRS, or fentanyl analogs as they’re sometimes called. But after the DEA implemented the temporary class-wide ban, it never pursued permanency. The DEA kept extending the class-wide ban, which was most recently set to expire September 30. In 2023 the DEA began pursuing permanent scheduling of seven FRS: para-chlorofentanyl, ortho-chlorofentanyl, meta-fluorofuranyl fentanyl, ortho-methylcyclopropyl fentanyl, beta-methylacetyl fentanyl, tetrahydrothiofuranyl fentanyl and para-fluoro valeryl fentanyl. In June, the DEA proposed permanent scheduling for three other FRS once covered by the class-wide ban.