By the time the Adair Fire Department arrived, the trailer and its contents, including poly totes full of lactic acid, were on fire.

A semi-trailer fire at a rest stop on I-80 Tuesday led to a lactic acid spill near Adair. The Iowa Department of Natural Resources says it is investigating after approximately 550 gallons of lactic acid spilled in the incident.

The Iowa Department of Natural Resources is investigating a lactic acid spill at a rest area along Interstate 80 east of Adair.