The chemical hydroxypivalic acid neopentylglycolester, which is used in the manufacture of lacquers, leaked into the river via the factory's cold water pipes.
“This is something that shouldn't happen,” BASF spokeswoman Ursula von Stetten told The Local. “For now, production has been stopped until we can fix the problem.”
Von Stetten added that an investigation had been launched to find the source of the problem.
The company said that there was no danger to people in the area or the environment due to the amount of dilution caused by the water. If anything, the water near the leak could sting the eyes of swimmers braving the Rhein.