Understanding Cocaine and its Metabolite: Benzoylecgonine (BZE)
When addressing allegations of drug driving involving cocaine, two key compounds must be considered: cocaine itself and benzoylecgonine (BZE), its primary metabolite. The law establishes different legal limits for each of these substances, both of which are crucial in determining potential liability in a drug driving case.
Cocaine in the Body and Legal Limits
Cocaine is a fast-acting stimulant that is rapidly absorbed into the bloodstream. However, the body also metabolises it at an accelerated rate. For drug driving cases in the UK, the legal limit for cocaine in the bloodstream is 10 micrograms per litre (10µg/L) of blood. This threshold has been set to support a near-zero tolerance policy, as even small amounts of cocaine consumption are likely to exceed this limit. While the limit is not technically zero, it is sufficiently low to ensure that any intentional use of cocaine will almost certainly result in an individual testing above the permitted level.
Benzoylecgonine (BZE) and its Role in Drug Driving Cases
Once cocaine is consumed, it is broken down in the liver, producing benzoylecgonine (BZE). Unlike cocaine, BZE lingers in the system much longer, sometimes accumulating with repeated use. The legal threshold for BZE in the blood is 50µg/L. This significantly extends the timeframe in which a person can be prosecuted for drug driving, as BZE remains detectable long after the effects of cocaine have worn off. Importantly, BZE itself does not impair driving ability, but the law does not require proof of impairment—merely the presence of the substance above the legal limit is sufficient for a conviction.
Police Testing Procedures for Cocaine Use
Roadside Drug Testing:
Police officers have the authority to conduct preliminary drug tests at the roadside if they suspect a driver has used drugs. This typically involves a mouth swab test (also known as a ‘drug wipe’), which can detect both cocaine and cannabis. An officer may request this test if:
- The driver appears to be under the influence of drugs;
- A traffic offence has been committed;
- The driver has been involved in an accident.
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Indicators of cocaine use that police officers may observe include:
- Dilated pupils
- Excessive sweating
- A clenched jaw
- Tremors or twitching
- Rapid speech or difficulty completing sentences
- Erratic or reckless driving
- Overconfidence, aggression, or euphoria
If a roadside drug test returns a positive result, the driver will be taken to a police station for further testing, typically involving a blood sample. Notably, roadside swabs are not legally admissible as evidence in court, so a formal blood test is required to determine whether the driver was over the legal limit.
Blood Testing Procedures
Drivers should always consent to providing a blood sample unless they have a valid excuse, such as:
- A diagnosed phobia of needles (a mere dislike is not sufficient)
- A medical condition preventing blood withdrawal, such as haemophilia
**Refusal to provide a sample without a reasonable excuse will likely result in a separate charge of failing to provide a specimen, which carries similar penalties to drug driving itself**
Once a blood sample is collected, it is sent for forensic analysis. While awaiting the results, the driver is typically released under investigation. If the results confirm that the driver exceeded the legal threshold for either cocaine or BZE, the police will decide whether to proceed with prosecution.
Drug Testing in Hospital Cases
In cases where a driver is hospitalised following an accident, blood may be drawn under stricter medical and legal protocols. If the driver is unconscious or otherwise unable to consent at the time, police may later request permission to analyse the sample. Legal representation is highly recommended before responding to such requests, as consent may impact the outcome of the case.
Issues with Blood Sample Analysis
Potential Errors in Testing and Storage
Drug testing processes are subject to stringent forensic procedures, but errors can occur. Blood samples must be stored in refrigerated conditions to prevent degradation. Cocaine, in particular, is known to biodegrade over time into BZE if improperly stored. This can artificially reduce the detected cocaine level while increasing the BZE concentration.
Delays in Analysis and Possible Defence Strategies
Laboratories often take weeks or even months to analyse blood samples. If testing occurs more than 101 days after collection, there is an increased likelihood that cocaine will have degraded into BZE, potentially leading to unreliable results. Expert forensic toxicologists may be able to challenge the validity of the analysis if degradation has occurred, which could form the basis of a defence in court.
Legal Consequences of Drug Driving Convictions
A conviction for drug driving with cocaine or BZE over the legal limit results in severe penalties, including:
- A mandatory minimum driving disqualification of 12 months (or 3 years for a second offence within 10 years)
- An unlimited fine
- A community order, which may include unpaid work
- A custodial sentence of up to 6 months (reserved for serious or repeat offenders)
It is important to note that while being convicted for multiple drugs can increase sentencing severity, BZE and cocaine are treated as a single substance for sentencing purposes since BZE is simply a metabolite of cocaine.
Common Misconceptions and Ineffective Defences
Some drivers attempt to defend against drug driving charges using the following arguments, but these are generally unsuccessful:
- I was exposed to someone else using cocaine’ – This is not a valid defence, as the law does not require deliberate consumption for a conviction.
- ‘I have a high tolerance’ – The prosecution does not need to prove impairment, only that the limit was exceeded.
- ‘I drank coca tea’ – While coca tea can cause a positive test, its consumption is illegal in the UK and not a recognised defence.
- ‘Medical necessity’ – Unlike cannabis, there are virtually no legal medical uses for cocaine in the UK that would serve as a defence in court.
Defending a Drug Driving Charge
If you have been charged with a drug driving offence relating to cocaine or BZE, it is crucial to seek expert legal assistance as soon as possible.
There are multiple defence strategies that can be explored, including:
- Challenging the reliability of blood test results
- Identifying procedural errors in the police investigation
- Questioning the accuracy of forensic testing
NEXT STEPS: Free Legal Advice from M.A.J Law
M.A.J Law are a specialist team of driving defence solicitors. We believe that every motorist has the right to independent legal advice. For that reason, we offer every motorist free specialist initial advice no matter what your circumstances.
If you’re facing drug driving charges, consulting with a specialist solicitor is essential to protect your rights and ensure that the proper legal procedures are followed. Call one of our specialists today on 0151 422 8020.
