Table 3.

Contaminants identified within 1007 samples of illicit fentanyl

Fentanyl Precursors	Others
4-Phenyl]amino-1-phenethylpiperidine (4-ANPP)	Phenothrin (Pyrethroid)
4-anilino-N-phenethylpiperidin (Phenethyl 4-ANPP)	1-hexadecene, 1-hexadecanol (surfactants)
Fluoro Phenethyl-4-ANPP	Phenylpropanamide (fentanyl degradation product)
Fluoro-4-ANPP
Meta-methyl 4-ANPP
4-anilino-N-phenethylpiperidin (Phenethyl 4-ANPP)
1-Propionyl-4-Anilinopiperidine
4-Anilinopiperidine
1-Phenethyl-4-Propionyloxypiperidine
1-Phenethyl-4-Hydroxypiperidine
4 N-Methyl Norfentanyl