Arkema shares fell sharply on Thursday after two explosions were reported at its flood-hit chemical plant in Crosby, Texas.
Chemicals were released into the atmosphere after Arkema's U.S.-based complex sustained significant damage from Tropical Storm Harvey. One police officer helping to secure the site was reportedly taken to a nearby hospital after inhaling fumes, while nine others admitted themselves as a precaution.
Residents living within a 1.5 mile (2.4 kilometer) radius of the French chemical group's site had been evacuated as the company warned there was a risk of explosions and fire.
Arkema said further explosions of organic peroxides stored on site were possible and urged people to stay away as the fire burns itself out.