An ammonia gas leak at an ice factory sent more than 160 workers to the hospital in Thailand.

Billowing clouds of the toxic white vapour engulfed the factory, injuring dozens of people along the Chaiyaporn Vidhi Road in Chonburi province on April 17.

Medics and rescue personnel arrived at the scene and asked locals to clear a one-kilometre radius around the factory.

Local media reported that more than 160 people who experienced were confined for various injuries including dizziness, breathing difficulties, and vomiting blood due to the chemical fumes.

Residents reported hearing a loud noise shortly before the ammonia gas seeped out of the building, which had reportedly suffered another leakage several years ago.

Bang Lamung district chief Weekit Manarotekit said firefighters have closed the factory's ammonia valves and doused the area with water to neutralise the gas.

He said: 'The provincial industry office will investigate whether the factory was at fault or not. 

'The number of injuries was over 100, with most of them suffering from difficulty in breathing. They were taken to hospitals in Pattaya, Bang Lamung, and Si Racha. 

'The district office has also opened set up an evacuation centre for residents waiting for the area to be cleared.'

Meanwhile, factory manager, Boonanun Pattanasin, said the cause of the leak is being investigated.

He said: 'We will fully compensate all expenses for local residents who were injured. They only need to inform us. 

'This ice factory is only used for storing ice and water before distribution.'

Ammonia is a substance used in several industries, such as seafood processing or producing concentrated latex. It is a refrigerant often used in large-scale refrigeration systems.