Overview
- About 1,000 liters of concentrated formic acid escaped from a hazardous‑materials truck at a rest area on the A61 near Weilerswist, creating a large corrosive spill.
- Firefighters warned the acid can cause burns and that warm temperatures may produce easily flammable vapors that raised an explosion risk if ignited.
- Police and fire crews cordoned the scene and closed the A61 in both directions for several hours before reopening the northbound lane for traffic.
- Responders grounded the truck to prevent sparks and have called HAZMAT specialists to pump out and remove the remaining acid; authorities say no prior accident was observed and the cause of the leak is under investigation.
- Formic acid is used in industries such as textiles, leather and feed treatments, its concentrated form can harm skin and lungs, and the incident disrupted regional traffic while emergency teams work to fully secure the site.