Phosgene leak at Chempark Dormagen sends up to 25 workers to hospital; no life-threatening injuries reported
A phosgene-containing liquid escaped at the Chempark Dormagen site early on 20 June, triggering an ammonia vapour curtain that contained the cloud before it could spread beyond the plant perimeter.
What happened
A phosgene-containing liquid leaked at the Chempark Dormagen (North Rhine-Westphalia) in the early hours of 20 June 2026. The operators said pre-installed safety measures activated immediately and a steam-ammonia wall was deployed to neutralise the toxic substance. The phosgene cloud was stopped quickly.
Casualties and medical response
Between 19 and 25 employees were taken to several hospitals with suspected contamination, according to a Cologne police spokesman. None were in a life-threatening condition. On first examination the workers were symptom-free but were kept under 24-hour observation because of the hazard posed by phosgene.
They have no symptoms indicating illness or injury. We just have to rule it out.
Some patients had already been discharged by the evening.
Environmental monitoring and public reassurance
Measurement vehicles from the plant fire brigade and the Cologne and Dormagen professional fire services checked adjacent residential areas and detected no anomalies. A Chempark spokeswoman noted that residents might have smelled the ammonia, which has a strong, unpleasant odour but is harmless.
That is not harmful.
Investigation
Police have opened an investigation. A spokesman said there were no indications of third-party involvement.
We are currently proceeding on the basis of a technical defect or an operating error.
The exact cause is still to be determined.
The site and the substance
Phosgene is used as a precursor for plant-protection products and pharmaceuticals. Around 70 chemical companies operate production plants at the Chempark Dormagen site.
