Water-reactive substances

Water-reactive substances[1] are those that spontaneously undergo a chemical reaction with water, often noted as generating flammable gas.

The use of acid-resistant gloves and face shield is recommended for safe handling; fume hoods are another effective control of such substances.

[4] Water-reactive substances are classified as R2 under the UN classification system and as Hazard 4.3 by the United States Department of Transportation.

The classification of substances as water-reactive is largely a consideration for the safety of firefighting and transportation operations.

[5] All chemicals that react vigorously with water or liberate toxic gas when in contact with water are recognized for their hazardous nature in the "Approved Supply List",[6] or the list of substances covered by the international legislation on major hazards[7] many of which are commonly used in manufacturing processes.