Nitrous oxide

There is currently no method for detecting laughing gas in the body, for example in the breath, blood or saliva. The length of time nitrous oxide remains in the body and exactly how it affects driving ability has also been unknown until now. This study describes techniques that are most suitable for detecting nitrous oxide in the breath, blood or saliva in the context of law enforcement and criminal investigation. Based on this study, it was not possible to establish a limit above which the effect on driving ability is too great, so further research is necessary.

 Nevertheless, Jan Ramaekers, professor of psychopharmacology at Maastricht University, has a clear warning: ‘During the brief period of intoxication with nitrous oxide, it is impossible to drive a car.’ According to co-researcher Frederick Vinckenbosch, even when the initial intoxication has passed, there are still small residual psychomotor effects that appear to last for at least 45 minutes.

Measurement techniques

During the study, promising measurement techniques were tested in the laboratory at the research organisation TNO and validated for usability, partly on the basis of breath and blood samples from test subjects. The effect of the use of nitrous oxide on behaviour was tested by researchers at Maastricht University on 24 test subjects. Head of police drug enforcement operations in the Netherlands, Willem Woelders, is pleased with the research results: ‘This study shows that you can detect laughing gas in the breath and blood, and that the use of laughing gas affects driving skills. This is something we have already seen in our daily policing activities, in many traffic accidents. The study also provides a starting point for the future development of a measurement technique which will enable us to improve policing in relation to nitrous oxide use in traffic.’

Driving ability

The researchers recommend further research to identify precisely what aspects of driving ability are negatively affected by nitrous oxide and to what extent. This could also determine the concentration of nitrous oxide at which the risk of accidents becomes too great. Other follow-up research may provide more clarity as to whether and under what conditions a saliva test is suitable as a detection method. The recent study was conducted on behalf of the Dutch police and the Police and Science Research Programme. A summary is available free of charge from the websites www.politie.nl and www.politieenkennis.nl.