Safety water-reactive chemicals

Occupational Safety and Health Administration (OSHA), 1996. Hazard Information Bulletin, Water Reactive Chemicals, Hazardous Materials Not Covered Under 29 CFR 1910.119, July 3, 1996. 

Fire detection and sprinkler systems are beneficial but if used with high bay racking consideration should be given to incorporating inter-rack sprinklers which counteract the chimney effect of a fire. Where sprinklers are fitted care should be taken that no water-reactive chemicals are stored. The advice of the local fire prevention officers, sprinkler suppliers, insurance surveyors and safety advisers should be sought on storage and rack layouts and on the arrangement of the sprinklers. 

Pyrophoric and other spontaneously combustible substances will generally be identified as such on their product literature, material safety data sheets (MSDSs), or International Chemical Safety Cards (ICSCs). If transported, these substances should be identified as DOT/UN Hazard Class 4.2 materials for shipping purposes and labeled as spontaneously combustible. For pyrophoric substances, the NFPA 704 diamond for container or vessel labeling has a red (top) quadrant with a rating of 4, indicating the highest severity of flammability hazard (NFPA 704, 2001). Note that pyrophoric materials often exhibit one or more other reactivity hazards as well, such as water reactivity. 

Housing two reactive chemicals that would generate toxic fumes when mixed within the same enclosure is an inherent safety blunder. According to the EPA report, three of the tanks had a total of 630,000 gallons of flammables. One of the tanks contained 340,000 gallons of sodium hydrosulfide (NaSH) as a 45% solution in water. One tank contained Briquest, a cleaning agent solution, and another was nearly filled with a relatively non-hazardous material. [11-12]... 

Mr. Ellison is president of Cerberus Associates, Inc. and as a private consultant, has responded to both transportation and fixed facility hazardous material incidents throughout the state of Michigan. He has acted as incident commander, safety officer, and response specialist at scenes involving chemical fires, water reactive materials, and shock sensitive materials. He has provided chemical and biological counterterrorism training to members of hazardous materials (HazMat) teams, police Special Weapons and Tactics (SWAT) teams, and Explosive Ordinance Disposal (EOD) teams. 

The potential hazards of most water-reactive materials are generally well known because of the precautions required for their safe handling. Substances that are water reactive will nearly always be identified as such on their MSDSs or International Chemical Safety Cards. They may be identified as DOTAJN Hazard Class 4.3 materials for shipping purposes and labeled as "dangerous when wet." However, some water-reactive materials... 

Adhesives can set or cure by carrier (solvent or water) evaporation, chemical reaction, or thermal activation. Chemically reactive adhesives solidify primarily by a chemical reaction of one or more components in the adhesive formulation. It should be noted that solvent welding cementing processes or solvent-borne adhesives are in disfavor due to environmental, safety, and health concerns and regulations. As a result, waterborne adhesives and heat-activated adhesives are replacing solvent-based adhesives in many applications. 

Chemical substances present in a process plant may react with each other, with air, or with water, causing safety problems. This chemical interaction is based on the chemical reactivity of each substance and with other substances present in the plant. As a potential process hazard, the chemical reactivity of any substance should be considered in the following contexts ... 

Most general-purpose release agents have been developed for this market in part because of their low toxicity and chemical inertness and do not usually present health and safety problems. Some of the solvent dispersions require appropriate care in handling volatile solvents, and many supphers are offering water-based alternatives. Some of the sohds, particularly finely divided hydrophobic sohds, can also present inhalation problems. Some of the metallic soaps are toxic, although there is a trend away from the heavier, more toxic metals such as lead. The reactive type of release coating with monomers, prepolymers, and catalysts often presents specific handling difficulties. The potential user with health and safety questions is advised to consult the manufacturer directly. 

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