Emergency services feared they could be dealing with a white powder chemical emergency when Tuesday's hot weather set off a fire extinguisher at Flaxmere's temporary library.
Police and the Fire Service were called to the Swansea Rd building after library staff reported a book return drop-box had been sprayed with a suspicious white powder.
But after donning protective chemical suits and breathing apparatus, firefighters discovered the powder was from an extinguisher set up in the metal box. The extinguisher had been set off after temperatures swelled under yesterday's hot sun.
The incident was attended by firefighters from Napier who were in Hastings dealing with a bomb scare at Parkvale.
Fire Service Napier senior station officer Mark McGill said staff at the library were not aware of the powder-based extinguisher system in the drop-box and firefighters needed to treat the situation with caution.
"We didn't know what it was until we got inside. It was a matter of investigating it and you have to take precautions. It's just par for the course."
One advantage of having powder-based extinguishers in the dropbox was that no books were damaged as a result of the discharge.
"I think we brushed them down and that was it," Mr McGill said.
The Swansea village warden's house is being used as a temporary library while a major upgrade of the Flaxmere Community Centre is under way.