Fire Service shift commander Megan Ruru said the evacuations were a precaution because of arcing powerlines.
Western Bay of Plenty head of road policing Senior Sergeant Ian Campion told the Bay of Plenty Timse further evacuations were possible.
"There were concerns that a number of bottles released gas and some when off the side of the road way," he said.
"They've [New Zealand Fire Service] initially said 24 hours. There may be further evacuations later this morning, once the fire service assesses the scene."
Fire crews are managing the safe recovery of the hazardous materials and it is not clear at this stage how long the road will be closed. Further updates will be issued throughout the day.
There are no available detours between Tauranga and Katikati so the alternative for traffic is via the Kaimai Ranges and Matamata.
There has been another crash on SH29 which is the alterative route motorists are using between Tauranga and Katikati because of the SH2 closure.
It is a three vehicle crash, believed one truck and two cars. One injury has been reported but it is not believed to be serious .
The road is still open but the area needs to be passed with care.
In addition to this, police are dealing with two fatal road crashes in the Eastern Bay of Plenty and Waikato.
The first occurred in Rotorua at approximately 6.30am this morning at the intersection of Amohau Street and Ranolf Street, Rotorua. The crash involved a moped and a car which has resulted in the death of the female rider of the moped who was in her 70s.
The second incident has occurred on SH1 Putaruru. A car travelling south away from Putaruru has collided with a truck travelling north. At least one man from the car is dead as a result of that crash. Police are still trying to ascertain if there were any other people in that vehicle.
Investigations are continuing into both of these crashes and it is too early to say whether either crash was weather related but torrential rain is making road conditions treacherous.
Police are urging all motorists to take extra care.
"We've had a long dry summer and the sudden downpour is making roads extremely slippery. As winter fast approaches there is a need to adapt to the changes, slow down and drive to the conditions", a police spokesperson said.
Police are also urging drivers to give vehicles a winter road check to ensure they are up to standard with roadworthy tyres. Those on two wheels should make sure they are appropriately equipped.
Daylight savings increases the need for motorcyclists, mopeds and cyclist to ensure they are visible, have the correct lights on and to wear reflective clothing. Police recommend that you do not cover your reflective clothing with back packs or rain jackets.
Any witnesses to the crash in Rotorua are asked to contact the Rotorua police on 07 348 0099. Witnesses to the Putaruru crash are asked to contact Tokoroa Police on 07 885 0100.
