
The accident forced authorities to block the road for about three hours to remove the 170 cylinders.
The accident took place at about 9.30pm on Sunday on highway No 1095 (Mae Hong Son-Pai) near the Suksasong Koh School Mae Hong Son in Ban Pang Moo, which is eight kilometres north of the city.
The driver of the six-wheel truck, identified only as Jamlong, was slightly injured.
Police suspect the driver was speeding when it was raining and he lost control on a curve in the road.