Horsham parents have raised concerns after discovering laughing gas capsules scattered across the town centre.
A reader said they found the capsules, believed to be used to contain gas nitrous oxide, along Springfield Road.
The capsules have also been spotted in other areas in the town centre including close to the bus stop.
Concerns were raised over fears people were using the gas to get high and then leaving the capsules in the town centre where children could get hold of them.
One dad of two said: “It is really not the sort of thing you want young children picking up.”
Nitrous oxide is a colourless gas that is most commonly found in the pressurised metal canisters discovered in the town.
When inhaled it can cause a throat spasms and stop people from breathing.
Police have been approached for comment.