Eight people have been taken to hospital after a suspected chemical mishap at a Sydney hotel.

Emergency services were called to the Pullman hotel opposite Hyde Park at about 9am on Wednesday following reports hydrogen chloride and chlorine gas had spread through the air-conditioning from the 22nd floor, the deputy superintendent for New South Wales ambulance service, Steve Vaughan, said.

Vaughan said his understanding was an employee had erroneously mixed chlorine and hydrochloride on the pool deck, and the gases spread through the ventilation system.

Some hotel patrons left after smelling the gas, but all people were evacuated from two floors of the hotel. Paramedics treated 30 patients for eye irritation and respiratory problems. Eight people were taken to the Sydney Eye hospital and St Vincent’s hospital.

All were in a “very very stable condition” and expected to make a full recovery, Vaughan said.

The Pullman hotel has been contacted for comment.