Water-Reactive Substances

classification scheme defines water-reactive substances as substances which are liable to become spontaneously flammable or to give off flammable gases in dangerous quantities by interaction with water. Water-reactive substances include, among others, alkaline metals (Na, K, Li, etc.), hydrogenates, and organometallic compounds. 

Their hazards are evaluated by the amount of flammable gas generated when a sample is put into water (U.N. Recommendation, Japanese Fire Services Law). 

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Suong oxidizers have more potential incompatibilities than perhaps any other chemical group (with the exception of water reactive substances). It is safe to assume that they should not be stored or mixed with any other material except under carefully controlled conditions. Common oxidizing agents listed in decreasing order of oxidizing strength include ... 

Water-Reactive Substances Water-reactive substances will chemically react with water, particularly at normal ambient conditions. For fire protection purposes, a material is considered water-reactive if a gas or at least 30 cal/g (126 kj/kg) of heat is generated when it is mixed with water (NFPA 704, 2001), using a two-drop mixing calorimeter. 

Water reactive Substance that reacts with water, often producing a vigorous exothermic reaction. 

Explosive substances Inflammable substances Water reactive substances Oxidizers... 

Reactive chemicals sometimes cause an explosion after long storage. The cause of the explosion may be the generation of an explosive peroxide. In order to avoid such accidents, one should be familiar with the atomic groups which generate peroxides. These groups are listed in the table 3 41. Based on Bretherick s book, a table 8 of spontaneously combustible substances, water—reactive substances, and unstable substances has been prepared. This table is in the Japanese edition of this book. It may be helpful for individuals to prepare similar tables of structural formulas specific to hazardous substances by using data from references. 

Spontaneously Ignitable Substances and Water—Reactive Substances... 

NOTE Flammable components do not cover pyrophoric, self-heating or water-reactive substances and mixtures because such components are never used as aerosol contents. 

Many inorganic and organic chemicals are irritants to the eyes, skin, and respiratory tract. Concentrated acids and bases are highly corrosive. Highly water-reactive substances such as bromine pentafluoride or other interhalogen compounds can bum the skin. 

H = Health hazard F = Fire hazard R = Reactivity hazard Ox = Oxidizing agent W = Water-reactive substance... 

Fire hazards posed by water-reactive substances such as alkali metals and metal hydrides, pyrophoric substances such as metal alkyls, strong oxidizers such as perchloric acid, and flammable gases such as acetylene require procedures beyond the standard prudent practices for handling chemicals described here (see sections 5.C and 5.D) and should be researched in LCSSs or other references before work begins. In addition, emergency response to incidents involving these substances must take their special hazards into account. 

The size of your worksite and workforce, processes used, materials handled, and the availability of onsite or outside resources will determine your training requirements. Discuss any special hazards your site(s) may have, such as flammable materials, toxic chemicals, radioactive sources, or water-reactive substances. To minimize confusion, clearly communicate who will be in charge dining an emergency and provide any evacuation route maps you have prepared. 

Water-reactives substances AUtali/alkaline earth metals Sodium, potassium... 

Water reactive substances, causing production of toxic gases acid chlorides, thionyl chloride, aluminum chloride, oleum Preferably single level structure in separate fire compartments no contact with water permitted via piping or water connections max. 250 tons per fire compartment max. 500 tons per building block storage with pallets max. 2 rows or 8 ft deep, max. 3 layers or 12 ft high... 

Reactivity Characteristic of substances that have a tendency to undergo violent chemical change (examples are explosives, pyrophoric materials, water-reactive substances, or cyanide- or sulfide-bearing wastes)... 

Did the employer inform the fire brigade members of special hazards, such as storage and use of flammable liquids and gases, toxic chemicals, radioactive sources, and water-reactive substances that they may encounter during an emergency ... 

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