One Australian is among the 135 people who died in the Beirut explosion at a port warehouse district, where 2750 tonnes of ammonium nitrate had been stored.

A stockpile of between 6000 to 12,000 tonnes of the highly explosive material is stored at Orica's Kooragang Island plant in the Port of Newcastle.

Chemical engineer Keith Craig says the plant is just three kilometres from Newcastle's CBD, with residents as close as 800 metres to the facility.

"We'd have an even worse explosion if you can imagine it," he told AAP on Thursday.

"It would flatten Newcastle."

Mr Craig notes while the risk of an explosion in Australia is low, a small accident would cause huge impacts.

"That tiny window of risk could be a catastrophic outcome," he said.

"You just don't have that sort of plant in the community."

Mr Craig, who is a member of the Stockton Community Action Group, says concerned residents have been lobbying Orica and the government to relocate the plant for years.

The Beirut blast has re-ignited the community's calls for the stockpile level to be lowered by storing some of it near the Hunter's coalmines before relocating the plant completely.

"We've seen what happened in Beirut and it's time to move on," Mr Craig said.

"The risk is just not worth it."

Orica insists its operations at Kooragang Island are highly regulated by authorities and comply with NSW government risk assessment criteria.

"Orica has stringent practices in place to ensure the safe storage and handling of ammonium nitrate (AN) at its Kooragang Island facility," the company said in a statement on Wednesday.

"It's important to note that there has not been a single incident involving the storage of AN in the Kooragang Island site's 51-year history."

The facility's ammonium nitrate storage areas are fire resistant and built from non-flammable materials, Orica said.

Australian Associated Press