A smashed mercury thermometer prompted an emergency services call-out to Whangarei's Orrs Pharmacy.
The thermometer was broken about 8.30am yesterday and was cleaned up by staff at the time, but Whangarei fire service senior station officer Brad Cunningham said when some staff started feeling "headachy" later in the day, emergency services were called.
"They [the staff] did the bulk of the clean-up with rubber gloves, disposing of the gloves and the thermometer in the toxic waste bin. Some of them felt a little headachy later on and thought it might be because of the mercury so we were called," he said.
Mr Cunningham said because there was a small amount of mercury, "less than a teaspoon", treating patients included giving them fresh air and ventilating the area.
"Any residual mercury that might be left over will be sprinkled with sulphur and it absorbs it, and that's done with rubber gloves and the gloves and the sulphur will be disposed of in the toxic waste bin," he said.
Orrs Pharmacy operations manager Kathi Jeeves said the pharmacy was following standard protocol. Staff were seen by ambulance staff but no one was harmed.
The liquid form of mercury is especially dangerous because it vaporises at room temperature. When it vaporises, it fills the air with tiny, invisible mercury atoms that are scentless and soluble in oils or fats.
If mercury vapour is inhaled, it is easily absorbed by the body, where it gets into the lungs and from there into the blood and the brain. The nerve poison can cause sleep disorders, agitation, and paralysis.