Prime Minister Scott Morrison has hosed down concerns Australia is at risk of a similar explosion to the catastrophe that killed at least 137 people in Lebanon.
The massive ammonium nitrate blast in Beirut has trigged fears about Newcastle's stockpile of the substance, three kilometres from the NSW city's CBD.
While 2750 tonnes detonated in the Lebanese capital, between 6000 and 12,000 tonnes are believed stored at Newcastle.
But the prime minister is adamant strict regulation in Australia is the key difference between the two countries.
"What happened in Beirut is just the most awful of tragedies and a terrible accident," Mr Morrison told 2GB radio on Friday.
He said Beirut's port is Hezbollah-controlled and the chemicals had been next to a fireworks dump for six years.
"These are not the circumstances of Australia. Those materials, there are very strict regulations on how they are used," Mr Morrison said.
The maritime union is warning of a "ticking time bomb" on Australia's coast due to inadequate shipping regulations.
MUA national secretary Paddy Crumlin said urgent actions were needed to protect the Australian coastline, as well as workers and nearby residents at ports that handle dangerous cargoes.
"The situation in Beirut, where a dangerous cargo arrived on an unseaworthy flag-of-convenience vessel that lacked the ability to safely store it, could easily be repeated in Australia," he said.
"Last year, 85,000 tonnes of ammonium nitrate moved through the Port of Newcastle alone - 30 times the amount that devastated Beirut - posing a significant threat to safety," he said.
The union wants tighter regulations to ensure dangerous goods are carried on vessels registered in Australia and crewed by locals with appropriate training and security checks.
One Australian was killed in the devastating explosion that injured more than 5000 and left widespread destruction across the city.
The federal government is weighing up more support for Lebanon to cope with the devastating fallout after pledging $2 million to the relief effort.
Australian Associated Press