Firefighters were called out to a chemical incident in Kinghorn on Tuesday, it has emerged.
Appliances from Burntisland, Lochgelly and Methil were mobilised to the incident in Strathmore Street, where they were told that a thermometer smashed in a sink and the mercury had entered the waste pipe on Monday night.
One of the residents was unwell after the incident, after coming into contact with the mercury. The crews evacuated the property and then awaited advice from the local hazardous materials officer.
Scientific Services, based in the Strathclyde area, arrived and took vapour samples then, helped by Fife Council workers, removed traces of mercury from the sink.
An ambulance crew also attended and paramedics carried out precautionary checks at the scene on two of the residents, who refused to attend hospital.
One of the residents was later asked to attend the accident and emergency unit by the Fife NHS public health adviser.
The Scottish Environment Protection Agency (Sepa) and Scottish Water were also told of the incident but were not required to act.