The Critical Role of Hair and Hair Wash Testing in Child Custody Cases

How Testing the Hair “Wash” Can Change the Presentation of Court Case

In child custody cases, the stakes couldn't be higher—especially when there are concerns about a child's environmental exposure to illegal substances. Not only the accuracy, but the methods and reporting employed by the toxicology lab, can have a profound impact on the decisions made by the courts.

In one such case, involving a mother and her young daughter, the importance of testing both hair and hair wash samples was brought into sharp focus. If you’d like to hear this story first hand, watch our on-demand webinar “Contamination of Toxicology Samples in Child Custody Cases.”

The Case: A Mother, a Daughter, and Methamphetamine Exposure

In this case, a five-year-old girl was at the centre of a custody battle. There were serious concerns about her environment, as her mother had a history of methamphetamine use. The court ordered a hair strand test (HST) to determine whether the child was being exposed to methamphetamine and, more critically, whether she had ingested the drug herself.

The toxicology team was instructed to conduct a segmented drug hair test on the child. This method involves cutting the hair into segments, where each 1 cm of hair represents approximately one month of growth. By doing this, the team could assess the child’s level of exposure to methamphetamine over a three-month period.

The Results: What the Hair Drug Strand Test Told Us

The segmented hair testing of the daughter revealed the following methamphetamine levels:

• Segment 3 (Oldest segment): 660 pg/mg

• Segment 2: 390 pg/mg

• Segment 1 (Most recent segment): 220 pg/mg

On the surface, these results were concerningly above the Society of Hair Testing (SoHT) cut off level: Drug usage was present in the hair. However, this was only part of the story.

 

The Hair Wash Test: A Crucial Insight

In addition to testing the hair segments for drugs, the toxicology team also tested the hair wash to evaluate the impact of environmental drug contamination. When conducting a hair strand drug test, it’s important to wash the hair first to remove external contaminants. After the wash, the lab is left with two samples: The hair and the hair wash. Testing the hair can provide insight about active drug use while testing the wash can provide insight about passive exposure.

The results of the hair wash showed:

• Hair Wash: 960 pg/mg

This result was startlingly higher than the levels found within the hair segments themselves. When comparing these results with those of the mother, a stark contrast emerged. The mother’s hair wash results showed much lower levels than her hair strand, confirming that she had indeed consumed methamphetamine. But for the daughter, the high levels in the hair wash, paired with the decreasing levels in the hair segments, told a different story.

Interpreting the Data: The Importance of Hair Wash Testing

At first glance, the segmented hair strand test might suggest that the child had ingested methamphetamine. However, the elevated levels found in the hair wash strongly indicated that the methamphetamine detected in the child’s hair was likely due to environmental contamination, not consumption. Environmental contamination of hair samples can look like touching a child's hair, kissing a child on the head, or when the child sleeps on a pillow contaminated with the parents sweat. Children’s hair is especially susceptible to contamination as it is more porous than adult hair.

The child’s older hair segments—those further from the scalp—showed higher levels of methamphetamine. This suggested that these segments had been exposed to contamination for a longer period, likely from her environment rather than direct ingestion. 

Without the hair wash data, one might mistakenly conclude that the child had been using or given methamphetamine. However, the hair wash provided crucial context, helping to differentiate between environmental exposure and ingestion of a drug.

Conclusion: Ensuring Accurate Results in High-Stakes Cases

This case highlights the critical importance of comprehensive testing in child custody cases. By including both hair follicle and the hair wash tests, toxicologists can provide a more accurate interpretation of whether a child has been externally exposed to drugs or has actually ingested them.

Clearly, a child living in an environment where drugs are being used is undesirable, but legally, this is quite different to a child actively consuming the drug. In cases like this, where the outcome can significantly impact a child's future, ensuring the integrity of the testing process is essential. The hair wash test serves as a vital tool in preventing false positives, ensuring that the court's decisions are based on the most accurate and reliable data possible.

At AttoLife, all children's hair strand tests are routinely washed prior to testing. In a similar way to the above case, both the hair follicle and the wash residues are tested in the lab to examine the hypothesis of external contamination. 

If you are a Family Law Solicitor or Local Authority who orders toxicology tests, please get in touch for any enquiries or you can ask us for a quote.