53 citations
,
November 1997 in “Journal of Forensic Sciences” Darker hair in guinea pigs holds more codeine than lighter hair.
63 citations
,
August 1996 in “Forensic Science International” Cosmetic treatments like bleaching and perming can greatly reduce opiate levels in hair, possibly leading to false-negative drug tests.
14 citations
,
January 1996 in “Journal of Forensic Sciences” Hair can absorb and transfer opiates when soaked in water, with damaged hair absorbing more.
48 citations
,
July 1996 in “Human & Experimental Toxicology” Human enzymes can detoxify harmful substances but might also increase their cancer risk.
1 citations
,
August 2006 in “International forensic science and investigation series” Hair testing is a reliable method for detecting workplace drug use when done with proper sample preparation and confirmation.