Five people have been potentially exposed to dangerous chemicals, two of whom were hospitalised, after a spill at Warners Bay on Thursday morning.
Firefighters who responded to the call around 11.30am said a drum of corrosive liquid chlorine was tipped over at a pool services company on Hillsborough Road spilling around 30 litres and reportedly leaving as many as five people with burns.
Paramedics were called just before midday and assessed those exposed, two of whom - a man and woman - were taken to John Hunter Hospital as a precaution, a spokesperson for the Ambulance said.
Meanwhile, firefighters from Charlestown and Cardiff Fire stations donned protective suits and breathing apparatus, and worked for more than an hour to clean up the spill, assess the building and declare the area safe.
A spokesperson for NSW Fire and Rescue said crews were able to decontaminate the area and render the business safe after about 90 minutes.