BERLIN German chemicals company BASF said it had shut down one of its facilities at its main Ludwigshafen site after a breakdown at the facility led to a brief release of nitrous gases (NOx).
The company said the incident at the northern part of the site occurred at around 0600 GMT and nobody was injured.
Authorities have been informed, the company said in a statement on Friday.
"The facility has been shut down and the emission of NOx has been stopped," BASF said. It does not yet know the reason behind the breakdown.
A spokesman said the leak occurred when the plant switched itself off briefly, and added that the gases were released for a couple of minutes only.
(Reporting by Victoria Bryan; Editing by Hugh Lawson)