Cocaine Drug Driving Offences

The legal limit for Cocaine is 10 micrograms per litre of blood (10ug). This is a zero tolerance limit. If convicted, you would receive a 12 month driving disqualification. 

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Drug Driving & Cocaine


Illegal Drug

Legal Limit

Cocaine 10µg%

Cocaine is a powerful and highly addictive controlled substance. Depending on how it is administered, cocaine can be a rapidly acting drug.

Will cocaine affect your driving?

The effects of cocaine on driving will depend on;

  • how much is taken,
  • the person’s tolerance to the drug, and
  • the use of any other drugs, including alcohol.

The stimulant effects of cocaine last for only a short period of time following which the after-effects commence. It has been reported that one-off use of cocaine by tired individuals can produce an improvement in attention for a short period of time with subsequent improvement in performance of simple tasks. As the tasks become more complex, however, this improvement may not occur.

The after-effects of cocaine use include;

  • Poor concentration and coordination
  • Drowsiness
  • Lapses of attention and ignoring stimuli such as traffic light changes
  • Visual impairment, primarily caused by an increased sensitivity to light

A study of motorists driving under the influence of cocaine found that, although they displayed symptoms of cocaine use, nearly half performed normally on field sobriety tests.

How long does cocaine stay in your system?

Cocaine will remain in your system for up to three days following use – or even longer in frequent users. Cocaine levels peak in the blood an average of 30 minutes after ingestion.

Any given drug’s presence in your system is often measured by its ‘half-life’. This is the period of time required for the amount of drug in your system to be reduced by one-half.

The half-life of cocaine is 1 hour. If you took 50mg of cocaine at 8:00pm, by 9:00pm there would be 25mg remaining in your system. By 10pm, there would be 12.5mg in your system, and so on… The quantity of the drug will reduce by 50% over each ‘half-life’ period.

So, how much cocaine before you’re over the limit?

Cocaine appears in blood after about 20 minutes, reaching a maximum concentration in 30 to 50 minutes.

Intranasal administration (through your nose) of a 32mg dose of cocaine (an average ‘line’) would produce a blood concentration of between 40-80 micrograms within 40 minutes (the legal limit being 10 micrograms). Your body would eliminate 50% of this within one hour.

If, for example, you consumed a 32mg line of cocaine at 8:00pm, your blood concentration will peak at 60 micrograms in 40 minutes. Within one hour, your body will have eliminated half the amount, meaning your blood content at 9:00pm would be 30 micrograms. By 10:00pm, it would be 15 micrograms. By 11:00pm you’d be under the limit for cocaine.

The information from this page come from a study conducted by Edward J. Cone. The information above it based on averages and will vary from person to person. It should not be used as a calculation method to avoid driving whilst over the prescribed limit. Cocaine is a prohibited substance.