Blood alcohol testers are not as widely available as breathalysers; a blood alcohol tester requires a different style of analysis in order to give a reading. Ordinarily, blood alcohol testing is performed by a medical professional at the request of a driver who wishes to challenge a breathalyser reading - but there are other situations when it is necessary. When is blood alcohol testing required?
If a driver requests it
Breathalysers are compact, practical and (if they comply with Australian Standards) accurate to within +/- 10% of a given BAC level. However, in an in vivo situation, there are many variables which can make an estimated BAC reading from a breathalyser significantly above the person's actual BAC.
This is why police in every state are bound to advise drivers that they can request a blood alcohol tester reading to confirm the results of a breathalyser reading. The blood alcohol tester reading must be obtained within two hours of the detainment, or it is not considered as admissible evidence in court.
Anybody over the age of 10 who is admitted to hospital following a road accident must have a blood alcohol tester reading taken. This should occur unless there is a sound medical reason not to take the sample.
While it is not an offence to fail to request confirmation of your breathalyser-estimated BAC by blood alcohol tester, it is an offence to refuse a sample to be taken in the hospital following a road traffic accident.