A truck carrying ammonium nitrate crashed about 60km west of Coolgardie in Western Australia last night, closing a section of the Great Eastern Highway.
The driver lost control of the truck on the highway near Pumping Station Road at about 2.15 am.
A police spokesperson said ammonium nitrate had spilled onto the road, The West Australian reported.
The road was closed in both directions and is not expected to be reopened until later this afternoon.
The driver of the truck was not seriously injured.
Ammonium nitrate is a fertiliser that is highly flammable.
It is commonly used in the mining industry as an additive to explosives.