The Department of Labour (DOL), which is investigating the April blast and fire at the Icepak coolstores at Tamahere, has only today issued a fact sheet for industry on the safe use of flammable hydrocarbon refrigerants – the type of gas used at Tamahere.
Unknown to firefighters and few outside Icepak, a highly explosive hydrocarbon refrigerant, HyChill-50 or HR22/502, was being used at the Tamahere coolstore when it exploded and caught fire on April 5, killing firefighter Derek Lovell and injuring seven others.
The issuing of the fact sheet by the DOL only after the fatal fire highlights how little prepared authorities were for the use of hydrocarbons in the New Zealand refrigeration industry. This is despite their wide promotion within New Zealand and overseas as an environmentally friendly replacement for ozone depleting CFC and HCFC refrigerants, which also contribute to global warming.
The Government backed promotion of hydrocarbons included a $60,800 grant to Icepak by the Energy Efficiency and Conservation Authority to cover the costs of trialling the refrigerant, including safety equipment and gas sensors, at its Waharoa plant.
DOL regional manager Ona de Rooy said the DOL, which released an early report on the fire to Tamahere Forum in June revealing that the highly explosive propane-ethane gas was the refrigerant used by Icepak, said the gas was “an important line of inquiry for the investigation team.”
The information gathering stage of the investigation was nearly completed, she said in a statement.
“This stage has taken time because the investigation is substantial, technically complex and involves a number of parties.” These include the Police, NZ Fire Service, Environmental Risk Management Authority, the Waikato District Council, private companies involved in running and maintaining the coolstore, and several insurance companies.
The investigators have drawn on the expertise of the DOL’s hazardous substances advisers and occupational scientists. They have also brought in an external fire investigation expert and other experts to help prepare the safety information on hydrocarbon refrigerants.
“The following stage will be to analyse the information to identify what caused this explosion and fire, and what could have been done to prevent it,” de Rooy said. “Because of the complexity of the investigation we cannot put a time frame on when we will complete this stage.”
The final part of the investigation will be to decide what response is appropriate, she said.
The DOL was circulating the safety information to relevant industry groups and associations. It was also working with the Fire Service to ascertain the number of industrial sites using hydrocarbon refrigerants, and the scale of use.
DOL Principal Adviser on Workplace Health and Safety Bob Hill said that if hydrocarbon refrigerants escaped from refrigeration and storage systems they could mix with air to form a potentially explosive mixture. “So it is essential to have safe design of plant and control systems, adequate maintenance, and safe operating practices when using hydrocarbon refrigerants.”
The safety fact sheet is here: dol-hydrocarbon-refrigerant-fact-sheet