Nitrous oxide (laughing gas) remains detectable in the breath and bloodstream for at least 60 minutes after inhalation and it would be technically feasible to develop an instrument to detect it, according to researchers at Maastricht and Leiden universities, and the TNO institute.

In addition, the impact of the gas on driving ability immediately after it has been inhaled is so serious that it would be “irresponsible to drive”, researchers say.

“During the brief period of intoxication with nitrous oxide, it is impossible to drive a car,” said Jan Ramaekers, professor of psychopharmacology at Maastricht University.

“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 … many traffic accidents,” said police spokesman Willem Woelders.

“The study also provides a starting point for the future development of a technique that will enable us to improve policing in relation to nitrous oxide use in traffic.”

There is currently no method for detecting laughing gas in the body, in breath, blood or saliva but police are keen to have one.

In the three years to 2021 more than 60 people died in road accidents where nitrous oxide was thought to have been involved and the drug was a contributing factor in nearly 1,800 accidents.

Laughing gas was added to the list of banned drugs from January 2023 alongside marijuana. That makes the possession, trade and production of the drug a crime, although users are not prosecuted.

The researchers recommend further research to identify precisely what aspects of driving ability are negatively affected by nitrous oxide and to what extent. Other follow-up research may also provide more clarity as to whether and under what conditions a saliva test would be suitable as a detection method.