Can bleached hair be tested for alcohol and drugs?

Blood Testing Drug & Alcohol Testing Hair Testing Nail Testing The Science What Affects Testing
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Hair Bleaching

Before a hair drug or alcohol test, your client may surprise you with  a new bleached haircut, but will this affect the hair drug or alcohol tests?

Hair drug test and bleached hair

Whenever a drug is consumed (smoked, injected, snorted or ingested in any way) the drug metabolises within the body.

The drug compounds, metabolites, will be inside the hair as it grows. Bleaching the hair can remove between 40-80% of metabolites found in the hair strand. If multiple bleaching attempts are made a participant can remove all drugs from their hair. A worrying situation and one of the reasons why so many “blonds” arrive at sample collections.

So why does bleaching remove drugs from the hair? It’s due to how bleaching reacts with your hair to change its colour. Bleaching will crack and damage the strand, this can cause the leaching of the metabolites out of the hair, hence removing some of evidence of drug use.

As not every drug is incorporated the same the level of “leaching”, it will depend on the drugs that the person has allegedly taken, as some drugs are more detectable in hair than others. For example, cannabis is a difficult drug to detect in head hair, and slightly more difficult in body hair.  

As mentioned above the possibility of detecting drugs in hair will  also depend on how many times a person has bleached their hair. If they’ve bleach their hair on a regular basis, it will be likely that no drugs can be detected, or if they are, they will be at very low levels. However if the hair has only been bleached once and this was only a couple of weeks before sampling, it may still be possible to detect the drugs.

An alternative to taking head or body hair due to bleaching or lack of samples, is fingernail testing. Fingernails are made out of a protein called keratin, this is the same substance that produces hair. Fingernail testing is extremely accurate but cannot give a month by month overview.  

Hair alcohol testing

Similar to hair drug testing, if the hair of your client has been damaged on multiple occasions due to the bleaching process, or if they don't have enough hair to sample, then DNA Legal may not be able to get an accurate reading.

However to combat this, DNA Legal can take blood samples from your client as well as fingernail and toenail samples. The only limitation with blood testing is that it covers a 30 day period instead of a 3-6month period

Want to know more?

If you would like to know more about this subject, or have any other queries then feel free to call 0203 4243 470 or request an online quote here

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