Waikato council authorities are asking pregnant and breastfeeding women to move temporarily outside of an area where a fire has been burning near Hamilton.
The Waikato Regional Council said a precautionary health notice had been issued to residents within three kilometres of Puke Coal's landfill in Pukemiro.
The fire has been burning at the site since August.
Waikato Regional Council resource use acting director Brent Sinclair, who is leading the incident management team for the landfill fire, said although the presence of dioxins had not been confirmed, as a precautionary measure following advice from the Waikato DHB public health unit, it was recommended that pregnant and breastfeeding women seek accommodation outside of the affected area, at least 3km from the site of the fire.
"This is the recommendation by Waikato DHB's public health unit and it holds until environmental testing shows dioxin levels aren't elevated or until we know the fire is out and no longer a risk," Sinclair said.