Reactivity and Incompatibility

HCN can polymerize explosively if heated above 50 °C or in the presence of trace amounts of alkali.

Storage and Handling

Because of its high acute toxicity, hydrogen cyanide should be handled using the ''basic prudent practices" of Chapter 5.C, supplemented by the additional precautions for work with compounds of high toxicity (Chapter 5.D) and flammability (Chapter 5.F). In particular, work with HCN should be conducted in a fume hood to prevent exposure by inhalation, and splash goggles and impermeable gloves should be worn at all times to prevent eye and skin contact. Never work alone with hydrogen cyanide. HCN should be used only in areas free of ignition sources. Containers of HCN should be protected from physical damage and stored in areas separate from ignition sources and other materials. Hydrogen cyanide should not be stored for extended periods (>90 days) unless testing confirms product quality.


In the event of skin contact, immediately wash with soap and water and remove contaminated clothing. In case of eye contact, promptly wash with copious amounts of water for 15 min (lifting upper and lower lids occasionally) and obtain medical attention. If hydrogen cyanide is ingested, obtain medical attention immediately. If HCN is inhaled, move the person to fresh air and seek medical attention at once. Specific medical procedures for treating cyanide exposure are available but usually must be administered by properly trained personnel. Consult your environmental safety office or its equivalent before beginning work with hydrogen cyanide.

In the event of a spill, remove all ignition sources. Cleanup should be conducted wearing appropriate chemical-resistant clothing and respiratory protection


Excess hydrogen cyanide and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines. For more information on disposal procedures, see Chapter 7 of this volume.

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