They declared it a hazardous material situation.
It happened around 11:50 p.m. Monday at the Arawak Paving Company on the 7500 of Weymouth Road in Hammonton, Atlantic County.
The site sits just off the Atlantic City Expressway in an otherwise remote area.
Authorities said the chemical in the burning tank was used for asphalt.
Crews called for multiple water tanker trucks.
The fire has been extinguished.
Authorities did not report any injuries or evacuations.