Hazards associated with the handling of liquid cyanide

Harmful fumes/gases

• Harmful fumes and gases are a threat to the Safety and Health of humans, the environment and the plant/process.
• Liquid Cyanide in contact with low pH substances, acid, strong oxidants and heat liberate Hydrogen Cyanide and Ammonia gases which is extremely toxic and flammable.
• Harmful gases that are produced in mineral processing plants are different in their reactive nature – such as poisonous, corrosive, flammable or explosive-able gases.

Cyanide Liquids (e.g. NaCN) – Hazard/Risk (hazardous substance)

• Sodium Cyanide is a light straw coloured liquid.
• Liquid Cyanide decomposes on heat exposure and liberates Hydrogen Cyanide and Ammonia gases which are extremely toxic and flammable.
• Flammable, toxic Hydrogen Cyanide gas is produced in the presence of low pH material, acids, acid salts and carbon dioxide. (Hydrogen Cyanide gas is odourless and colourless).
• Liquid Cyanide is extremely dangerous to humans and aquatic life due to its toxicity.

Storage / Transport

Store under lock and key or in a way that only skilled persons have access. Ensure ventilation when opening containers. Traces of HCN may adhere to solid product. Seal container hermetically immediately after use. Keep container tightly sealed and store in a dry, well-ventilated place. Ensure there are sufficient retaining facilities for water used to extinguish fires. DO NOT store together with acids. Keep away from food, drink and animal feedstuffs.

Fire / Explosion

Will not burn or explode. In the case of fire hydrocyanic acid may be released. Material is stable up to 1500 deg C. Under the influence of acids (as well as carbon dioxide) hydrocyanic acid is released which is combustible and may react with air to form explosive gas mixtures. Carbonic acid and water (air humidity) may cause hydrocyanic acid to be released.

Extinguishing Media

Evacuate area – move upwind of fire. Summon the Fire Brigade immediately. Fire fighters should wear full protective equipment including self-contained breathing apparatus. Use alkali powder quenching agent. DO NOT use water or carbon dioxide type extinguishers. Water used to extinguish fire should not enter drainage systems, soil or stretches of water. Contaminated fire extinguishing water must be disposed of in accordance with all local regulations. Fire residues should be disposed of in accordance with all local regulations.