A Response to Recent Concerns About Fairness in Family Court Testing
By Dean Clifton, AttoLife
We welcome the recent article “Drug and alcohol hair testing could be getting it wrong” (coramchambers.co.uk, 2025), which raises timely questions about the use of hair strand drug and alcohol testing in family courts. At AttoLife, we believe public scrutiny is important—but it must be paired with scientific clarity.
We agree on many of the article’s concerns, especially the need for expert interpretation and context. But we also want to correct some misconceptions. Here’s a breakdown of the article’s main points—and how they compare with best-practice testing protocols.
1. A Positive Hair Test Is Not the Same as Being a Drug User
“Currently it’s assumed that when drugs are found in the hair above a defined level then you are a drug user but we have copious amounts of data that shows that is not the case.”
— Paul Hunter, Forensic Testing Services
This is a critical point—and it’s one that accredited labs like ours make clear in every report. A positive result should never be viewed in isolation.
The defined levels (cut-offs) in hair testing are set by the Society of Hair Testing (SoHT), an international society of more than 300 experts. These cut-offs are based on past and current scientific literature, most recently updated in 2021 to reflect best practice. The aim is to ensure consistency of results and interpretation across laboratories worldwide.
However, these cut-offs are guidelines, not regulations. There is no requirement for labs to adopt them, which means some may apply their own thresholds and decision rules—leading to variation in results.
Additionally, claims that “copious amounts of data” show these cut-offs are unsuitable should be provided for peer review before being treated as valid points of discussion.
2. Interpretation Matters as Much as Testing
“The biggest failing at the moment is that services are instructing drug tests but not instructing an expert to carry out a full forensic investigation…”
— Paul Hunter
We strongly agree. A test result is just one piece of evidence. Our reports are not lab printouts—they are forensic documents designed to help courts interpret results in the correct legal and scientific context.
This is why we recommend Expert Witness Reports (EWRs). While we do provide results without interpretation when clients request it, we caution that skipping expert review can lead to misinterpretation. An EWR provides the court with clarity and ensures that all relevant biological and environmental factors are considered.
At AttoLife, our interpretation always goes beyond raw results. Our sample collectors document the donor’s substance use history, medications, and alcohol use over the prior 12 months, along with details of hair treatments and any other information the donor wishes to record. These declarations are factored into the report to provide courts with context.
3. Biological and Racial Factors Influence Drug Levels—And Must Be Interpreted Carefully
“Things like hair colour, race, how often you shampoo your hair… influence what’s found in the hair.”
— Paul Hunter
This is well documented in toxicology. Hair colour and ethnicity can affect drug concentrations, because some drugs bind strongly to melanin, which is more concentrated in darker hair. This means individuals with darker or curlier hair may show higher concentrations for the same level of drug use.
For example, certain drugs including cocaine and codeine are known to bind strongly to melanin. A 2011 study by Claudia Vignali and colleagues compared self-reported cocaine use with measured concentrations in hair. Among those declaring use 1–2 times per month, individuals of African descent had average concentrations of 14.98 ng/mg, compared with 3.99 ng/mg for Caucasian individuals. Despite this disparity, both levels were well above the SoHT cut-off of 0.5 ng/mg.
These findings underscore why hair testing requires expert interpretation. At AttoLife, we never equate a concentration value with a precise drug dose, and we always highlight where biological factors such as hair colour, type, or treatment may influence results. Courts should never rely on raw concentration values as “lines on a page” without context.
Learn more about Expert Reports and Hair Dying.
4. The Family Court Needs Better Toxicological Expertise
“If you were looking at the Coroner’s Court or criminal court, you’d have a proper clinical toxicologist… But when you are talking about someone’s baby potentially being adopted, the stakes are just as high.”
— Sarah Branson, Coram Chambers
We agree: the stakes in family law are as high as in criminal or coronial settings. That’s why all AttoLife reports are written and reviewed by toxicologists with combined expertise in forensic science and family law proceedings.
We also provide guidance on which test to order (e.g. abstinence vs. pattern of use) and regularly assist barristers to ensure interpretations withstand scrutiny in court.
This is not just about science—it is about justice.
5. Different Labs, Different Results?
“She paid for another test that came back negative, with the same piece of hair and same period of time, because of lab variation.”
— Sarah Branson
Lab variation is a reality of hair testing. Unlike liquid matrices such as blood or urine, hair is a solid matrix and inherently more variable. This is why a sufficient portion of hair must be collected to achieve a representative sample.
Differences between labs arise because each uses its own methodologies, instrumentation, and decision rules. To counter this, reputable labs participate in proficiency trials, where identical hair samples are distributed across laboratories and results compared. These trials reveal whether a lab’s results are consistent with peers and highlight any methodological issues. At AttoLife, we only use laboratories accredited to ISO 17025 standards.
It’s also important to recognise that all measurement science carries an intrinsic variation. This is known as the uncertainty of measurement, reflecting the small but unavoidable range of variability introduced by laboratory equipment, processes, and human factors. Many providers include this uncertainty in their service-level agreements, meaning that two tests on the same sample may report slightly different values—but these should fall within a narrow and predictable range.
We recognise that variation remains a challenge, and we actively support greater openness and sharing of methodologies to reduce inconsistencies across the industry.
6. Cheapest Doesn’t Mean Best
“Local authorities have contracts… purely on the basis of price.”
— Sarah Branson
We appreciate the budget pressures facing local authorities, but cutting corners on testing creates risks. Results that are poorly explained, or not reviewed by toxicologists, can prolong proceedings or even lead to miscarriages of justice.
At AttoLife, we advocate for responsible commissioning that prioritises scientific quality, transparency, and proper expert oversight.
Final Thoughts: Fairness Depends on Scientific Integrity
Hair strand testing is a powerful tool when done properly—and a dangerous one when it’s not. At AttoLife, we are committed to:
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Upholding rigorous scientific standards
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Offering expert interpretation, not just lab printouts
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Supporting courts and professionals with clear, contextual reporting
We welcome the opportunity to educate and engage with legal professionals who want to better understand testing science. If you’d like training, support, or case consultation, we’re here to help.
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