Experiments forcing animals to swim or inhale smoke will be banned under a law anticipated to pass in NSW, after the government moved amendments to exempt fish.
Animal Justice Party MP Emma Hurst's private members bill passed in the NSW parliament's upper house on Wednesday.
"A parliamentary inquiry in 2022 recommended these cruel animal experiments were banned, and finally they will be," Ms Hurst said in a statement following the bill's committal to the lower house.
"They can not be justified because of the cruelty that occurs but also because they are simply unscientific."
Liberal MP Jacqui Munro told the upper house the opposition would not be supporting the bill.
"There is a limited place for retaining the option to conduct certain animal research tests including smoke inhalation and swim tests," Ms Munro said.
She said she was only aware of one reputable research facility with links to major universities that carried out smoke inhalation tests, investigating air pollution, the impacts of bushfires, and smoking and vaping.
"These research projects are not being conducted in a frivolous matter and they're not occurring for fun," she said.
The government moved amendments in the upper house exempting fish from the forced swim test prohibition.
Agriculture Minister Tara Moriarty said the amendments clarified the bill's scope.
"One would be hard-pressed to say fish are forced to swim however this amendment simply is about ensuring that the intended scope of the prohibition is abundantly clear," she said.
Greens MP Abigail Boyd said the party did not oppose the amendments but described its "very strong suspicion".
"These amendments have been made simply to enable the government to accept this bill ... rather than putting forward their own bill," she said.
Ms Hurst said Ms Moriarty and Premier Chris Minns worked closely on ensuring a sensible policy was implemented.