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Little or no scalp hair
FTS have established a unique approach to testing body hair
FTS’s accumulated knowledge and experience of body hair testing provides the opportunity to obtain reliable evidence on drug and alcohol misuse. Using body hair as an alternative to scalp hair, FTS are able to differentiate excessive from non-excessive drinking. FTS now have sufficient data to establish cut-off’s for body hair and to provide an assessment of the period covered for each specific body hair sample tested for both drugs and alcohol.
Body hair testing also has the benefit that it is less susceptible to external influences such as hair treatments and also is often more protected from the risk of passive environmental contamination from drugs such as cannabis, cocaine and heroin.
Body hair cannot be segmented but can still monitor changes over time
Body hair samples cannot be segmented to provide reliable information on drug or alcohol use. However, FTS have now developed new techniques to help establish drug and alcohol use over specific time periods:
- Collecting two or more sequential body hair samples over 1 to 3 month periods can establish changes in patterns of drug or alcohol use.
- Shaving body hair from the same collection site each time also provides an accurate and defined history for substance misuse as an alternative to segmentation of scalp hair.
- Testing hair from more than one specific site on the body (leg, arm, chest, back, face) at the same time, enables differentiation of time periods, since each site has its own specific growth profile.
Background information on Body Hair testing
Although body hair grows at a similar rate to hair on the scalp its growth varies from approximately 0.65cm every 28 days to 0.9 cm every 28 days depending on the specific bodysite, compared to an average 1.0 cm every 28 days for scalp hair. However the most significant difference is the much higher proportion of dormant or non-growing hair (telogen) present in body hair compared to the scalp. Telogen hair can remain attached to the skin from around 2 to 9 months before dropping out
Body hair contains between 40% to 80% telogen hair depending where it is on the body. This means that a significant proportion of the hair that was growing 2 to 9 months ago, and which contains the drug and alcohol markers from this earlier period, is now mixed in with the growing hair, which represents drug or alcohol levels from the recent history. The length of the body hair also influences the history it represents. Consequently, FTS apply a calculation to include hair length and the approximate percentage of telogen hair for each body site, to establish the approximate history covered by each sample tested.
The resulting levels in body hair therefore represent an average of drug or alcohol use over an extended period but unlike scalp hair there is a bias to the older history, which can result in more carry over from earlier drug or alcohol use. When drug use is regular it can also lead to a concentration of levels in the hair relative to the amount of drug or alcohol use compared to scalp hair.