At  least 24 international apparel brands have pledged to immediately investigate the mass fainting “phenomenon” that has hit the Cambodian garment factories that supply them, the International Labour Organisation says.

Executives of global brands had pledged to work together “to determine the precise causes of  incidences of fainting among workers”, the ILO said after a buyers’ forum  in Phnom Penh this week.

The executives had “expressed the need for immediate action on behalf of the welfare of the workers”, the organisation said.

The mass faintings have drawn fresh attention to conditions in factories where brand-name clothing is produced for Western consumers.

Women had collapsed on several factory floors during the weeks leading up to the buyers’ forum, organised by the ILO’s Better Factories Cambodia program.

The program, which monitors all exporting garment factories, reported early last month that the factories complied for the most part with Cambodian labour laws and international standards.

Soon after the report was released, however, a wave of fainting incidents led to the hospitalisation of hundreds of workers from several factories that supply global brands and retail chains, including Walmart Canada.

The ILO said there had been 10 reported mass fainting events at garment factories this year.

It has identified numerous possible causes, including heath stress, chemical exposure, excessive overtime, inadequate nutrition, lack of occupational safety and health management systems, and unsafe hygiene and sanitation facilities, according to Better Factories Cambodia.

Tuomo Poutiainen, chief technical adviser at Better Factories Cambodia, said:   “More research is urgently needed to identify possible new causes that will explain the fainting phenomenon, as well as eliminate [causes] we know about.

“We will continue to monitor individual factories and to investigate every reported instance of fainting.”

Chea Mony, president of the Free Trade Union of Cambodian Workers, said he supported investigations of mass fainting but recommended a pre-emptive approach be adopted.

“I want the ILO and relevant agencies to find ways to prevent mass fainting from happening. It is better than investigating after it happens,” he said.         

Unionists have pointed to the low pay workers receive – about 30 US cents an  hour – as a major cause of the fainting.

Staff are working longer hours and skipping meals to make ends meet, they have said.