Taipei: Four employees of a beef-noodle restaurant in Daan District, Taipei, were hospitalized after a suspected carbon-monoxide (CO) poisoning incident.

According to Focus Taiwan, two employees – a 25-year-old woman and a 33-year-old man – who exhibited more severe symptoms were rushed to Wanfang Hospital, while the other two male employees, aged 33 and 37, were later taken to Cathay General Hospital for treatment. Police and firefighters received reports of the incident at 12:58 p.m., and dispatched two firetrucks, four ambulances, and 13 rescue workers to assist the four employees who were feeling unwell but fully conscious.

Personnel from Tai Wa Gas Equipment joined the firefighters at 1:24 p.m. to inspect the accident site, after which they determined the incident was likely caused by incomplete gas combustion. According to a statement from Daan Precinct’s Anhe Road Police Station, the CO levels in the kitchen were 93 parts-per-million (ppm) when emergency services arrived, and returned to 0 once the site was ventilated.

The statement also said the restaurant has not officially opened yet, and the employees were testing out recipes when they started feeling unwell. Daan Precinct warned that CO primarily comes from the incomplete combustion of gas, which is why proper ventilation is crucial when using gas equipment, adding that places with poor ventilation should use certified equipment with a forced exhaust feature to ensure safety.