The Boys and Girls Club in Ottawa's west end.The Boys and Girls Club in Ottawa's west end. (CBC)

A Boys and Girls Club in Ottawa's west end has reopened after a pool maintenance worker was sent to hospital after exposure to chlorine gas Tuesday morning.

The worker mistakenly mixed hydrochloric acid — used as a cleaner — with another chemical, creating chlorine gas, according to Marc Messier, a spokesman with Ottawa Fire Services.

A hazardous materials team was sent to the club at 2825 DuMaurier Ave. around 6:15 and ventilated the building.

The worker was overcome by the fumes and treated on the scene by paramedics who said he had a serious inhalation injury. The 57-year-old man was taken to hospital but is expected to recover.

Chlorine gas "is nasty stuff," said Lt. Ron Fitzgerald, who is with the fire services haz-mat unit.