Key Points:

A Fire Service inquiry into a fatal explosion and fire at a Waikato coolstore is calling for an overhaul of regulations and standards at coolstores.

The report says it is unclear whether the facility at Tamahere, about 12km south of Hamilton, had fully complied with its requirements to manage and use flammable refrigerants.

It found there were no warning signs of hazardous materials nor a gas stenching agent to alert firefighters who attended the callout, with no risk assessment plan, on April 5.

"If the firefighters had smelt the usual stenching agent associated with propane they would have been made aware of the potential dangers."

The report said the coolstore was "always at risk from fire" with very large quantities of combustible material in storage and did not have the facilities onsite to deal with fire.

"There were no compliant fire detection or protection systems or hydrants and very limited firefighting water," it said.

The huge blast at the 4000 sq m Icepak Coolstore in Tamahere about 12km south of Hamilton, killed senior station officer Derek Lovell and seriously injured seven other firemen.

The inquiry team report identified factors which could have avoided the risks and injuries to the responding firefighters.

It said The Hazardous Substances and New Organisms (HSNO), regulated by the Environmental Risk Management Authority, should be amended so coolstores and the refrigerants they contain, were subject to appropriate controls.

It has also recommended large-scale flammable gas installations should by law require inclusion of stenching agents in the gas.

The report found firefighters followed operational instructions but said "ideally" fire crews should have visited the facility as part of their risk planning process.

It was uncertain whether the firefighters had turned on their breathing apparatus when entering the building.

"Whether or not they had done so did not affect the outcome of the incident in this case."

It has since recommended pre-incident planning process are needed to identify high-risk buildings, including those outside the urban fire district.

The regulatory regime as a whole needed to be reviewed to promote information sharing about hazardous substances.

The report identified nine factors which might have prevented the tragic outcome:

* having hazardous substances regulations applied fully at the installation;

* prior notification to the Fire Service that there were hazardous substances at the premises;

* receipt of an application for approval of an evacuation scheme;

* a familiarisation visit by local Fire Service staff;

* Fire Service awareness of the large scale use of flammable refrigerants in New Zealand;

* warning signs at the coolstore;

* smell added to refrigerant gas, so firefighters would know of its presence;

* gas detectors to warn fire crews;

* fire crews to use a portable gas detector.

"This indicates that the fundamental cause of the incident may lie in part in systemic defects in the regulatory environment and the communication between the various regulatory agencies," the report said.

"This is an issue that may deserve wider investigation by the Government."

Firefighters Union spokesman Derek Best said the coolstore was "a disaster waiting to happen", and it was extraordinary so many potential safety nets were absent.

Of additional concern was comment in the report that there was another coolstore using highly flammable and potentially explosive gas.

"Given the circumstances surrounding the existence of the Icepack coolstore, no one really knows whether or not there could be more," Mr Best said.

"In any event, where is the other coolstore identified in the report?"

The inquiry team, headed by Paula Beever, was originally given until July to report back, with that deadline extended 30 days to August 12.

Fire Service chief executive Mike Hall had 10 days to consider its implications and recommendations before providing comment back to Dr Beever.

In June, the Department of Labour identified the gas that exploded at the coolstore.

It was Hychill-50, previously known as HR22/502, and was a highly flammable propane gas.