The National Emergency Management Agency (NEMA) has issued a national warning following White Island's volcanic eruption on Monday afternoon.
The event has been deemed as a "moderate volcanic eruption" and is hazardous to the those in White Island's immediate vicinity.
NEMA has warned that despite White Island's marine position off the coast of the Bay of Plenty, ashfall may impact areas far away from the volcano.
"Effects of a volcanic eruption can be experienced many kilometres from a volcano," it wrote.
The agency warned those in or near the affected ashfall areas should be aware of the potential health hazard.
"Consider staying indoors. Volcanic ash could be a health hazard, especially if you suffer from breathing difficulties," NEMA says.
"When indoors, close all windows and doors to limit the entry of volcanic ash."
The agency recommends wearing a dust mask or using a cloth to cover the nose and mouth when caught in volcanic ashfall.
"Protect your eyes by wearing goggles. Wear eyeglasses, not contact lenses as fine ash will get under the lens," it advises. The friction of the ash beneath the lens can cause corneal abrasions.
People should stay updated through the radio and television.
NEMA, which replaced the Ministry of Civil Defence and Emergency Management on December 1, also reminds people to stay out of designated restricted zones and remain vigilant.
Other advice includes placing damp towels at thresholds to limit the entry of volcanic ash when indoors.
GeoNet has since lowered the eruption's alert level to three and its current volcanic activity to minor.
