One firefighter was killed and twenty were injured after inhaling ammonia gas released from a 60-ton container in the Emek Hefer region on Thursday.
The area around the Hod Hefer factory was cordoned off, and nearby residents have been instructed to remain indoors. The warning was lifted a few hours later.
Firefighter Samer Asli from Kfar Kara was reported missing after arriving at the scene of the leak, and was found and evacuated only after 11 P.M., and died despite attempts to resuscitate him.
One of the twenty injured suffered moderate injuries; the rest are in light condition, suffering from nausea, vomiting and shortness of breath.
Internal Security Minister Yitzhak Aharonovich said the incident will be investigated.
Over 30 firefighting crews, from three regional councils, have been summoned to the scene.
Ammonia, a colorless but strong-smelling gas comprised of nitrogen and hydrogen, is a naturally occurring chemical compound that is also mass produced for industrial use. It serves as a raw material for various products and also as a warehouse refrigerant.
Ammonia is corrosive and can cause severe irritation of the eyes and respiratory system. In high concentrations, it can cause serious burns, blindness, lung damage and even death.
The vast majority of industrial ammonia in Israel is stored in a large tank in Haifa Bay. From there, it is shipped to various factories, most commonly for use as a refrigerant in food factories.
The leak occurred when a two-to-three centimeter breach opened in the pressurised container, which authorities fear could erupt.