Description
Hydrogen Cyanide (HCN) is a highly volatile, colourless liquid below 26°C (79°F), and a colourless gas above that temperature. It has a distinctive bitter almond odour, though not everyone can detect this smell, and its presence can also cause olfactory fatigue (loss of smell) at higher concentrations. It is one of the most rapidly acting and deadly poisons known.
Key Properties:
- Colourless: Invisible as a gas or liquid.
- Odour: Distinctive bitter almond smell. Crucially, about 20-40% of the population cannot detect this odour due to a genetic trait, and exposure to higher concentrations can rapidly cause olfactory fatigue, making the odour an unreliable warning sign.
- Extremely Toxic: Acts as a chemical asphyxiant by interfering with the body’s ability to use oxygen at the cellular level, leading to rapid cellular death. Exposure can be fatal within minutes.
- Flammable/Explosive: HCN gas is highly flammable and can form explosive mixtures with air.
- Density: Slightly lighter than air as a gas, but it disperses readily. It can also form heavier-than-air mixtures with water vapor.
- Volatility: Evaporates very quickly at room temperature.
Replacement Sensor, Part No. 17124975-B, Properties
| Gas Detected (Abbreviation) |
Sensor Type | Measurement | Response time (Seconds) |
Calibration Gas & Concentration |
||
|---|---|---|---|---|---|---|
| Range | Resolution | T50 | T90 | |||
| Hydrogen Cyanide (HCN) |
Electrochemical | 0 to 30 ppm | 0.1ppm | 25 | 80 | HCN 10 ppm |
Toxic Gas Sensor Cross-sensitivity Table
| Target Gas | Sensor | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CO | CO (H2 Low) |
H2S | SO2 | NO2 | Cl2 | ClO2 | HCN | HCl | PH3 | NO | H2 | NH3 | |
| CO | 100 | 100 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 20 | 0 |
| H2S | 5 | 5 | 100 | 1 | -40 | -3 | -25 | 10 | 300 | 25 | 10 | 20 | 25 |
| SO2 | 0 | 5 | 5 | 100 | 0 | 0 | 0 | – | 40 | – | 0 | 0 | -40 |
| NO2 | -5 | 5 | -25 | -165 | 100 | 45 | – | -70 | – | – | 30 | 0 | -10 |
| Cl2 | -10 | 0 | -20 | -25 | 10 | 100 | 60 | -20 | 6 | -20 | 0 | 0 | -50 |
| ClO2 | – | – | – | – | 20 | 100 | – | – | – | – | – | – | – |
| HCN | 15 | – | – | 50 | 1 | 0 | 0 | 100 | 35 | 1 | 0 | 30 | 5 |
| HCl | 3 | – | – | 5 | 0 | 2 | 0 | 0 | 100 | 0 | 15 | 0 | 0 |
| PH3 | – | – | – | – | – | – | -100 | 425 | 300 | 100 | – | – | – |
| NO | 25 | 40 | -0.2 | 1 | 5 | – | – | -5 | – | – | 100 | 30 | 0 |
| H2 | 22 | 3 | 0.08 | 0.5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 100 | 0 |
| NH3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 100 |
The table above reflects the percentage response provided by the sensor (top row) when exposed to a known concentration of the target gas (column 1).
The numbers were measured under these environmental conditions: 20 °C (68 °F), 50% RH and 1 atm.
The specified cross-interference numbers apply to new sensors only and may vary with time as well as from sensor to sensor.
“-” means no data available.
This table is given as a reference only and is subject to change.
