James Nutt
CANSFORD LABS
Debunking myths in hair testing - part 1
on Jan 27, 2025
At Cansford Laboratories, we, as in our founders, initially introduced hair strand testing to the UK almost 30 years ago – and so as pioneers, we’ve watched how hair analysis has grown and evolved over the last few decades. It’s been quite an amazing journey.
Talk on socials and LinkedIn
Lately however, there’s been more talk about hair analysis on social media, especially on LinkedIn, which is great to see. But we’ve found it’s also frustrating to come across some of the misinformation being shared around.
We know a lot of people in the field want to clear things up, so James Nutt, our Laboratory Manager and Expert Witness is kicking off the series with the first blog discussing the facts and “debunking myths about hair testing.”
Myth 1 – “Cut-off levels should not be used in hair analysis”
Many labs follow established cut-off levels for hair analysis to avoid reporting positive results from historic or unintentional substance use, such as one-off instances. The Society of Hair Testing (SoHT) guidelines, found here, outline key points about cut-off levels:
7.1 Cut-off is the value that enables identification of drug users.
7.2 When hair analysis is utilized in drug facilitated crimes (DFCs) or single intake/exposure cases, the cut-off is not to be considered but lower limit of quantification are required.
7.3 For hair analysis in children the cut-off is not to be considered but lower limit of quantification are required.
Aligning with specific scenarios
While there are valid reasons to avoid cut-off levels, these typically align with specific scenarios mentioned in the guidelines.
A primary challenge with hair analysis is the difficulty of conducting controlled studies. Unlike blood or urine testing, it’s impractical to administer the same drug amount to a large group and analyse identical hair segments for variations.
Robust accreditation
For labs accredited to ISO17025:2017 by UKAS, the use of cut-off levels is defined under "Critical Level of Interest or Cut-Off Concentration," as explained in UKAS LAB51 documentation:
“The concentration value around which a decision is often required. A method is usually deemed acceptable if, when used properly, it can establish within defined limits of measurement uncertainty, whether a concentration is above or below the critical level of interest. This is generally the Cut-off Concentration specified within Regulations or published Guidance”.
Society of Hair Testing (SOHT) set the standards by expert global consensus
The most widely accepted guidelines for hair analysis come from the SoHT. These guidelines reflect an international consensus of experts and are regularly updated, with the most recent updates for drugs of abuse testing in 2021 and general hair testing recommendations in 2022.
As leaders in the field, our company actively participates in shaping these guidelines. Alongside my colleagues, I’ve contributed to expert discussions where new consensus statements are developed.
Pictured: James presenting at the annual SoHT conference in Lisbon.
Once reviewed and agreed upon by SoHT members, these consensus statements are published on the SoHT website (www.soht.org). We take pride in being members of the SoHT and supporting these industry standards.
Happy to answer questions
If there's anything you'd like James or Cansford to clear up regarding hair testing, then please do get in touch. Either by email here info@cansfordlabs.co.uk, through our contact form here or through our live chat here.
James Nutt
James Nutt is Cansford’s Senior Reporting Scientist and Laboratory Manager. He has extensive knowledge and experience of toxicology in relation to family court, reporting and drug and alcohol testing.