The theft, from Clifton Park NHS Treatment Centre, happened over night between Monday 30 December and Tuesday 31 December 2013.
The cylinders which are all blue are either three feet or five feet in length. They all have white collar tags, with the manufacturer’s name BOC and details of the contents. The tags also have important safety advice written on them.
PC Nick Garbutt, of York Safer Neighbourhood Team, said: Although nitrous oxide is sometimes used recreationally, in this pure form it is hazardous to health and could even prove fatal. So I urge people not to take any risks.
Nitrous oxide can also be used to enhance the performance of specially modified cars. If you are involved in this hobby and can help to identify the people responsible for this theft, I urge you to contact the police immediately.
If you are offered of these cylinders for sale, please contact the police as a matter of urgency.
Anyone who can help to locate these bottles of nitrous oxide should contact York police straight away on 101, select option 2 and ask for Nick Garbutt. Alternatively, information can be emailed to email@example.com.
Or call Crimestoppers anonymously on 0800 555111, quoting reference number 12130225595.