In a SEVESO-rated agro-pharmaceutical products plant, fire broke out at 5:30 pm at the level of a dust removal filter on an aggregate manufacturing line. The phytosanitary product contained 5% metaldehyde (anti-slug), salicylic acid, a dye and wheat flour. The active ingredient, metaldehyde, was classified as noxious (Xn), though the finished product was not. The internal emergency plan was triggered. Technicians shut down the installation: electricity and gas supplies were cut prior to the site’s internal first responder intervention. The 2nd intervention team helped limit damage to the facility’s filtration assembly. External fire-fighters brought the fire under control at 6:50 pm, 15 to 20 min following activation of the internal emergency plan. The filtration system’s bag filters were destroyed; approx. 1 tonne of substances had burned. Combustion of the finished product did not emit a significant amount of toxic smoke. Extinction water was confined inside the workshop. A specialised subcontractor pumped the water and stored it in a basin while awaiting proper elimination. Wastes were destroyed at a certified disposal facility. The semolina stored in the silo was discarded in order to avoid any risk of fermentation. Two technicians present in the workshop complained of slight irritations and were admitted to hospital for observation; both were released at the beginning of the evening. The insurance company appointed an appraiser. Two hypotheses were forwarded: heating of the powder in the hopper’s bottom screw, and existence of a hotspot created by an electrical hopper heating cord. The cost associated with damage (equipment, disassembly/reinstallation, debris removal, semolina destruction) was assessed at €400,000, while operating losses due to shutdown of the granulation unit for an indefinite period amounted to €1 million. No environmental impacts were reported.