B-Sample Testing

What is a Road Traffic B-sample?

In the UK, when suspected of drink or drug driving, individuals are required to provide a blood or urine sample. The A-sample is retained by the police force for prosecution testing, while the B-sample is given to the individual. The B-sample allows for secondary analysis by an independent forensic service provider. Kingston Analytical Toxicology Services specializes in B-sample testing, offering services for defence cases. Our dedicated laboratory provides reliable and impartial forensic toxicology analysis, contributing crucial insights for individuals seeking an independent review of their case.

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What should I do with my B-sample?

It is critical that you keep the sample refrigerated and try to have it sent to a laboratory at your earliest possible convenience. Freezing the sample may result in cracks to the vial and therefore no challenge to the prosecution result would be possible.

Under no circumstances should you open the plastic bag that contains the sample, as this may invalidate the results of any analysis.

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Section 5 of the Road Traffic Act

In England and Wales, motorists can be convicted if they are found to be driving with blood or urine alcohol concentrations above the fixed limits. Depending on the nature of your sample, the limits are below.*

Sample	mg/100 mL
Blood	80
Urine	107

If you’ve had a roadside breathalyser test taken and require B-sample analysis, head over to our services and promptly send us your sample.

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Section 5a of the Road Traffic Act

In England and Wales, motorists can be convicted if they are found to be driving with certain drugs above a fixed limit. The drugs in question are listed below.

Controlled Drug Limit	µg/L of Blood
Amphetamine	250
Benzoylecgonine (metabolite of Cocaine)	50
Clonazepam	50
Cocaine	10
Delta-9-Tetrahydrocannabinol (Cannabis)	2
Diazepam (Valium)	550
Flunitrazepam	300
Ketamine	20
Lorazepam	100
Lysergic Acid Diethylamide (LSD)	1
Methadone	500
Methylamphetamine	10
Methylenedioxymethamphetamine (Ecstasy/MDMA)	10
6-Monoacetylmorphine (Heroin)	5
Morphine	80
Oxazepam	300
Temazepam	1000

The stipulated limits for these drugs operate similarly to the set limits for alcohol in drink driving cases. If your sample surpasses the specified limits for any of these drugs, you may face charges for drug driving under Section 5a of the Road Traffic Act.

In our extensive experience, the most frequently encountered drugs are cocaine and cannabis. This prevalence is largely attributed to the widespread use of roadside oral swabs, which exclusively test for these two substances. If you’ve tested positive for either of these drugs through a swab or suspect you’ve consumed any of the listed drugs, acquire the necessary analysis by purchasing our services and promptly send us your sample.

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Legal

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