State Highway 29 is closed in both directions after several containers fell from a truck, spilling chemicals on the road.
Photo: John Borren / SunLive
Waka Kotahi Transport Agency says the containers fell from the truck about 500m south of the Kaimai Summit.
The road is expected to remain closed for much of the day to enable clean-up, says a spokesperson for the roading organisations.
"Motorists are encouraged to delay their travel where possible."
Waikato Regional Council told RNZ the truck spilled 3000 litres of sodium hydroxide, also known as lye or caustic soda, and warned it may have entered a nearby stream. It advised anyone taking water downstream to exercise caution until more was known about the spill.
Photo: SunLive / Supplied
Detours are State Highway 36 and State Highway 5 via Rotorua or State Highway 27, State Highway 26 and State Highway 2 through the Karangahake Gorge and on to Tauranga.
The agency said the detours would add considerable time to journeys and were not suitable for High Productivity Motor Vehicles (HPMV).
"Visit the interactive Journey Planner websitefor up-to-date information on the road closures, detour routes and traffic in the area," it said.
Photo: SunLive / Supplied
This story was first published on SunLive and is used with permission. Additional reporting from RNZ.