Hydrogen Cyanide (HCN), also known as hydrocyanic acid, is a chemical asphyxiant with a musky and almond-like smell and a slightly blue colour. HCN is a very hazardous gas, as people often cannot smell it and are unaware of its presence, regardless of the concentration levels. Hydrogen Cyanide (HCN) gas is lighter than air and easily mixes with atmospheric gases, which creates a highly explosive and flammable mixture. Because of the high risk and danger, Hydrogen Cyanide monitoring systems are essential where there is a risk of exposure.
Hydrogen Cyanide is used heavily in manufacturing plastic, paints, and synthetic materials and can be used in pest control as a fumigant. Hydrogen cyanide can be released into the environment as a byproduct from smoke and fumes during industrial activity. Hydrogen Cyanide affects humans by disrupting the body’s use of oxygen in our organs and is exceptionally fatal. It can also harm the cardiovascular system, central nervous system and pulmonary system.
Gas Fact – Cigarette smoke contains hydrogen cyanide, and small amounts of cyanide compounds are naturally found in cassava, almonds, lima beans, and fruit seeds.
Industrial Applications of Hydrogen Cyanide
Hydrogen cyanide gas plays a critical role in multiple manufacturing processes. It is used or emitted in the following industries:
- Plastic manufacturing
- Paint and coating production
- Pest control (as a fumigant)
- Paper and pulp processing
- Chemical processing plants
In addition, hydrogen cyanide is a byproduct of industrial combustion, including burning fossil fuels, causing vehicle emissions, and even cigarette smoke. The widespread industrial use of hydrogen cyanide means that facilities must implement hydrogen cyanide gas detectors to comply with workplace safety standards and protect employees.
Hazards of Hydrogen Cyanide Exposure
Hydrogen cyanide is one of the most acutely toxic industrial gases, affecting the body’s ability to use oxygen at the cellular level. Exposure may result in:
- Shortness of breath
- Nausea, dizziness, and unconsciousness
- Blue skin pigmentation (cyanosis)
- Cardiac arrest
- Death, even after short-term exposure at high concentrations
A hydrogen cyanide gas detection system is vital to identifying leaks early and preventing exposure in chemical plants, textile facilities, fumigation chambers, and manufacturing plants.
Assessment of the Dangerous Toxic Load (DTL) for Specified Level of Toxicity (SLOT) and Significant Likelihood of Death (SLOD)
- Common synonym – Hydrocyanic acid
- CAS number - 74-90-8
- 'n' value - 2
- SLOT DTL (ppmn.min) – 1.92 x 10
- SLOD DTL (ppmn.min) - 4.32 x 10
- HCN Boiling point is 26 Celsius
- HCN Melting point is -13 Celsius.
FAQs – Hydrogen Cyanide Gas (HCN)
What is hydrogen cyanide used for?
Hydrogen cyanide is widely used in manufacturing plastics, synthetic fibres, and fumigants. It is also a byproduct of industrial processes like combustion.
What does hydrogen cyanide smell like?
It has a bitter almond odour, but many people cannot smell it, making odour an unreliable detection method.
How do you detect hydrogen cyanide gas?
A hydrogen cyanide gas detector or HCN monitoring system can detect even low concentrations in industrial or laboratory environments.
Is hydrogen cyanide explosive?
Yes. HCN forms highly flammable and explosive mixtures with air, especially in enclosed spaces.