More than 40 workers fainted at the Nanguo Garment Co. Ltd. in Preah Sihanouk province Tuesday and the company prevented other workers from leaving, the Phnom Penh Post reported.
A month ago more than 200 of the factory's workers fainted.
The province's labor minister suggested poor ventilation was the cause but consultant Maeve Galvin of the International Labor Organization Better Factories Cambodia said other factors were involved.
"It's a combination of heat stress, poor nutrition, and there is a psychogenic component, usually beginning with one person having [a] fainting [spell]," Galvin said.
Tuesday's fainting episode began with four female workers who went into convulsions after collapsing. The incident sent co-workers into a frenzy and other workers fainted.
Factory officials said they prevented workers from leaving because they feared the workers wouldn't return.