Bottled water containing fluoride is expected to hit shelves within six months in a move that has irked anti-fluoride crusaders.

Australia’s food safety authority decided to allow the voluntary addition of fluoride into packaged water today after lengthy appeals by the Australasian Bottled Water Institute.

Bottled water companies argued that lifting restrictions would increase consumer choice.

It is understood several will now move to include the chemical, which boosts dental health, in their products. The first bottles will hit shelves in less than six months.

Anti-fluoride advocate Keith Oakley denounced the move, saying it would make it harder for him and his colleagues to access water.

He said the move would also backfire.

“If they want to put fluoride in there, then that’s their problem. But bottled water sales will go down,” he said.

“It’s a bit disappointing but at the very least it should be labelled so I can still buy non-fluoridated water.”

Mr Oakley is a resident of Geelong where the most recent fluoride battle took place last month. He said the options available to opponents of fluoridation were getting smaller.

Since the introduction of fluoride into tap water last month, he has been buying bottled water and is trying to install a rainwater tank at home.

The Bottled Water Institute, which has been advocating fluoridated bottled water since 2006, said its campaign was driven by a need to offer customers with non-fluoridated water supplies a choice.

“We’re expecting any sort of negative response to be limited … but ultimately the market will sort itself out,” chief executive Geoff Parker said.

Food Standards Australia New Zealand will permit the addition of fluoride to non-carbonated packaged water to between 0.6 and 1.0 mg on the proviso that clear labels are also provided.

Meanwhile, the fluoride debate has been described as reaching levels of “health terrorism” in Victoria.

Anti-fluoride extremists have been blamed for a hand-delivered death threat to state MP Lisa Neville. Police are also investigating threats to blow up the city’s water infrastructure.

All state capitals have fluoridated water. Brisbane was the last to introduce it into the system this year.

Opponents argue fluoride is a poisonous industrial by-product of fertiliser with lasting and harmful side-effects.