Officials blamed food poisoning for sparking the mass fainting of about 40 garment workers in a factory in the Svay Rieng border town of Bavet on Monday afternoon.

Kao Hao, deputy police chief of Bavet, said the workers at the RKT factory in the town’s Tai Seng Special Economic Zone fainted after some of them suffered from food poisoning.

“They were sent to the local referral hospital, and returned home on [Tuesday] at 2pm,” he said.

“According to the doctor, a few of them got food poisoning, and at first, two or three fainted, and then other workers started to faint.

They were weak and when they saw their colleagues fainting, they immediately got dizzy, vomited and fainted as well.”

The National Social Security Fund said 1,806 workers fainted at the workplace in 2015, roughly the same number as the year before.

Most of the instances took place in garment factories, where explanations for the faintings range from lack of proper ventilation and bad smells from fumes to physical as well as mental exhaustion.