An ammonia leak at Steggles processing plant at Beresfield required a major response from Fire Rescue NSW crews last week.
Eleven people were treated by ambulance, with eight being transported to hospital suffering from vomiting, headaches, respiratory problems and nausea.
Fire crews set up an exclusion zone around the facility and evacuated up to 350 people. Once the leak had been isolated, Tarro and Newcastle Hazmat firefighters entered the site wearing breathing apparatus and protective clothing to monitor the levels of ammonia remaining.
Newcastle Hazmat has several gas detectors capable of detecting the amount of ammonia present in the atmosphere and determining whether these levels are dangerous to human health. At this incident, readings remained elevated for several hours.
Ammonia is lighter than air so will naturally dissipate into the atmosphere over time. Crews ventilated the site and undertook regular readings until the concentration of ammonia fell below acceptable levels.
Gas leaks are one of the most common call outs received by Fire Rescue NSW stations. Often gas lines are ruptured as a result of digging and earthworks around houses.
Before beginning any jobs that involve digging below ground level call Dial Before You Dig on 1100, or go to 1100.com.au to get free plans with the location of underground services.