Three staff members at Prince of Wales Hospital required medical treatment after a formaldehyde leak at the hospital’s Department of Clinical Pathology.

All three were in stable condition, a spokesperson from the hospital said.

The affected area was sealed off and authorities were immediately informed about the incident, the hospital said, adding that around 180 staff members in the department were evacuated before firefighters arrived.

Prince of Wales Hospital said clinical services were not affected.

According to a preliminary investigation, the formaldehyde was leaked while it was being transported by a chemical waste contractor, the hospital added.

It said it was very concerned about the incident and has urged the contractor to submit an investigation report as soon as possible and implement remedial measures.

The case has also been reported to the Hospital Authority through the Advance Incident Reporting System.