The law stipulates that those found guilty of the most serious acid attack offences face a maximum of life in prison. Other acid-related offences carry terms ranging between two and 30 years.
Ziad Samman, project manager for the Cambodian Acid Survivors Charity, said the law's passage was an important step towards addressing the scourge.
"It represents a formal acknowledgement that acid violence will not be accepted in Cambodian society, and that perpetrators will be held accountable by law," he said.
The new law must head to the upper house before being signed off by the king, but both steps are a formality, ahead of its likely introduction later this year.
Acid is cheap, widely available, and delivers terrible injuries with attackers typically targeting the victim's face.
CASC figures show 21 people were burned with acid this year.
Samman said 347 people had been attacked since 1984, with 36 of them children under 13. He said the true number of victims was likely much higher.//DPA