Use of Cyanide Salts


As little as 50 to 150 mg of these salts or their aqueous solutions can cause death. Poisoning can occur by inhalation of mists of cyanide solution and by inhalation of HCN produced by the reaction of metal cyanides with acid and with water.

Symptoms of non-lethal poisoning include weakness, headache, dizziness, rapid breathing, nausea and vomiting. These compounds are not regarded as having good warning properties.


For an untrained person, the risk of injury is high with the severity being serious or even fatal.

Who is likely to be injured?

The most likely injury is to the person using the material although production of hydrogen cyanide gas in an open laboratory could have serious consequences for all occupants.



  • Metal cyanide salts and the more toxic organic cyanide salts must not be stored on open shelves in the laboratory. They should be kept in a well ventilated and secure, preferably locked cupboard.
  • A COSHH Special Assessment must be completed and approved by the Safety Committee before any new use of these materials. Material can be issued by the Chemistry Stores only with the permission of the Safety Committee
  • The appropriate First Aiders who are qualified in the treatment of cyanide poisoning must be informed by the potential user and pre-warned of any planned work.
  • Reference should be made to an up-to-date Material Safety Data Sheet or Laboratory Safety Sheet.
  • Procedures using these materials must never be attempted by an untrained person.
  • Procedures using these materials must never be attempted out of normal working hours or over the lunch period when trained First Aiders may not be available.
  • Procedures using these materials must never be attempted by someone working alone and for larger scale operations, workers should operate in pairs.
  • All operations, including weighing material, must be carried out in an appropriately rated fume hood.
  • Appropriate personal protective equipment, i.e. impermeable gloves, lab coat and safety glasses, must be worn.
  • A large container of aqueous ferrous sulphate solution must be kept at hand for the immediate immersion of all equipment that has contained or contacted this material (paper, spatulas, etc.) and for the neutralising of small spills.


Training by a competent person is absolutely essential before this material is used


Level of Risk Remaining

Constant vigilance is required in the use of these materials but risks should be low if the procedures outlined above are followed.


Emergency Procedures

  • Skin Contact. Immediately wash with soap and water and remove contaminated clothing. Call PSSO (Ext 2691)
  • Eye Contact. Wash with copious amounts of water. Call PSSO (Ext 2691)
  • Ingestion. Obtain urgent medical attention. Call PSSO (Ext 2691)
  • Inhalation. Obtain urgent medical attention. Call PSSO (Ext 2691)

Back to Completed Risk Assessment Forms

Adapted with permission from School of Chemistry, University of Bristol