A chlorine gas leak closed the Arun Leisure Centre in Felpham on the morning of Friday, April 13.
A notice on the website of the centre’s operator, Inspire Leisure, at midday stated: “The leisure centre is closed until further notice.
“This is due to a chlorine gas outbreak in the main pool area.
“Professionals are on the scene to rectify the situation. We are sorry for any inconvenience this may cause.”
Firefighters were called to the leisure centre off the A259 Felpham Way just after 6.20am. They spent almost three hours there.
They identified the likely location of the outbreak as the pump room for the swimming pool.
A West Sussex Fire and Rescue Service spokeswoman said: “Firefighters wearing breathing apparatus and gas tight suits entered the pump room to check the extent of the leak.”
They isolated the chlorine cylinder valves. Four fire crews from Bognor, Littlehampton and Chichester were at the scene.