A play activity centre at Warrington was cordoned off and four people taken to hospital after cleaning chemicals being used in the kitchen produced chlorine gas.
The incident took place at Jump Warehouse, Chetham Court, Warrington, at 17.35 yesterday.
Two fire engine attended from Warrington.
On arrival Firefighters dealt with in an incident in the kitchen at Jump Warehouse where a small quantity of cleaning chemicals being mixed in a container caused a small amount of chlorine gas to be released. Firefighters cordoned off the area.
Two firefighters wore breathing apparatus to ventilate the kitchen using a large fan.
Environmental Health attended the incident and removed the container from the kitchen.
An ambulance was requested and four people were taken to hospital for a check up, because they may have inhaled the gas.
