A brief article from a presentation at the International Scientific Conference, by Cansford and Chromatox
Cansford Laboratories (UK) and Laboratórios Chromatox (Brazil) presented separately two papers at the Scientific Meeting of the Society of Hair Testing (SoHT) in Geneva in August 2013 – www.soht.org.
Cansford Laboratories was the only UK laboratory presenting at the SoHT – out of 53 scientific papers.
The two papers are about two very important matters in the forefront of hair testing at present. External contamination and workplace drug testing. The findings and conclusions from both papers were important contributions.
The paper presented by Cansford (Differentiating between consumption and external contamination when testing for cocaine and cannabis in hair samples by J.Nutt, L.Tsanaclis, K.Bagley, S.Bevan and J.Wicks.) showed that we could confidently use metabolite/parent drug ratios in conjunction with the analysis of the wash residues as tools in successfully differentiating use of cocaine from external contamination in the majority of the cases.
Our second drug paper was concerning the practices and misconception when using of hair testing in the workplace for the exclusion of drug users whose drug use would be incompatible with their activities. (Hair analysis in pre-employment of high-risk activities in Brazil by M.Andraus, L.Tsanaclis, C.Sodré, L.Morales, C.Pisaneschi, D. Silva, M.Salvadori and J.Wicks)
We found that the frequency of cocaine levels that were below cut-off levels were twice as much as those above cut-off levels. This confirms that many people do abstain from using drugs for sufficient time just to “pass the test”. This finding reinforces that there could be further benefits if companies were to monitor new employees randomly throughout their probationary period. Hair, urine or oral fluid testing could be used for this random testing programme.
We also found that there is a misleading generalisation that hair testing using body hair has a window of detection of 365 days. Whilst body hair cycle can have longer window of detection in comparison to head hair, it can only cover 365 days if the sample of body hair is sufficiently long. This is seldom true.
We believe that providers of hair testing services have the responsibility to offer their clients with clear and accurate information on the potential advantages of hair testing in the workplace and also with its limitations.