Phenyl fentanyl-d5 (hydrochloride) (exempt preparation) (Item No. 39197) is intended for use as an internal standard for the quantification of phenyl fentanyl (Item Nos. 25887 | 22551) by GC- or LC-MS. Phenyl fentanyl is categorized as an opioid.1 Phenyl fentanyl-d5 is regulated as a Schedule I compound in the United States. Phenyl fentanyl-d5 (hydrochloride) (exempt preparation) (Item No. 39197) is provided as a DEA exempt preparation. This product is intended for research and forensic applications.WARNING This product is not for human or veterinary use.