(The Associated Press circulated the following article on June 16.)
DOWNERS GROVE, Ill. — A white powder that spilled onto train tracks from a passing freight snarled travel for as many as 12,000 Chicago commuter rail passengers during Thursday’s evening rush hour, leaving many of them temporarily stranded.
Authorities later said the power was a common soap-making chemical and relatively harmless.
The spill occurred on the Metra commuter rail line that uses the Burlington Northern tracks from Chicago to Aurora, said Metra spokesman Tom Miller.
The powder apparently spilled from a Burlington-Northern freight train about 4 p.m., he said.
The powder was later identified as stearic acid, a material used to make soap and considered low in toxicity.
The substance was identified after hazardous material teams and the Illinois Environmental Protection Agency were dispatched to the Downers Grove station and commuter train traffic was halted at the peak of the evening rush.
Miller later said the tracks were clear as of 8:30 p.m. and normal service was expected for the rest of the night.
Stearic acid comes from animal and vegetable fats and is sometimes used in the production of soap and candles to make them harder and last longer. Its dust can be flammable.