IPCS INCHEM Home
HYDROGEN CYANIDE, LIQUEFIEDICSC: 0492
Hydrocyanic acid
Prussic acid
Formonitrile
May 2018
CAS #: 74-90-8
UN #: 1051
EC Number: 200-821-6

  ACUTE HAZARDS PREVENTION FIRE FIGHTING
FIRE & EXPLOSION Extremely flammable. Gives off irritating or toxic fumes (or gases) in a fire.  Gas/air mixtures are explosive.  NO open flames, NO sparks and NO smoking.  Closed system, ventilation, explosion-proof electrical equipment and lighting.  Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out. In other cases extinguish with powder, water spray, alcohol-resistant foam, carbon dioxide.  In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position. 

 AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR! 
  SYMPTOMS PREVENTION FIRST AID
Inhalation Confusion. Drowsiness. Headache. Nausea. Shortness of breath. Convulsions. Unconsciousness. Respiratory and cardiac arrest.  Use ventilation, local exhaust or breathing protection.  Administration of oxygen may be needed. Fresh air, rest. Half-upright position. No mouth-to-mouth artificial respiration. Refer immediately for medical attention. See Notes. 
Skin MAY BE ABSORBED! Further see Inhalation.  Protective gloves. Protective clothing.  Wear protective gloves when administering first aid. Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer immediately for medical attention. See Notes. 
Eyes MAY BE ABSORBED! Redness. Pain. See Inhalation.  Wear face shield or eye protection in combination with breathing protection.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Burning sensation. Further see Inhalation.  Do not eat, drink, or smoke during work. Wash hands before eating.  Rinse mouth. Administration of oxygen may be needed. NO mouth-to-mouth artificial respiration. Do NOT induce vomiting. Refer immediately for medical attention. See Notes. 

SPILLAGE DISPOSAL CLASSIFICATION & LABELLING
Remove all ignition sources. Evacuate danger area! Consult an expert! Personal protection: gas-tight chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Ventilation. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. NEVER direct water jet on liquid. 

According to UN GHS Criteria

flam;flameskull;toxicenviro;aqua
DANGER
Extremely flammable liquid and vapour
Fatal if swallowed, in contact with skin or if inhaled
Causes eye irritation
Very toxic to aquatic life
Very toxic to aquatic life with long lasting effects 

Transportation
UN Classification
UN Hazard Class: 6.1; UN Subsidiary Risks: 3; UN Pack Group: I 

STORAGE
Store only if stabilized. Fireproof. Cool. Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Store in an area without drain or sewer access. 
PACKAGING
Marine pollutant.
Do not transport with food and feedstuffs. 
HYDROGEN CYANIDE, LIQUEFIED ICSC: 0492
PHYSICAL & CHEMICAL INFORMATION

Physical State; Appearance
COLOURLESS GAS OR LIQUID WITH CHARACTERISTIC ODOUR. 

Physical dangers
The gas mixes well with air, explosive mixtures are easily formed. 

Chemical dangers
The substance may spontaneously polymerize if it is not stabilized. The substance may polymerize due to heating under the influence of bases, over 2% water, or if not chemically stabilized. This generates fire or explosion hazard. On combustion, forms toxic and corrosive gases including nitrogen oxides. The solution in water is a weak acid. Reacts violently with oxidants and hydrogen chloride in alcoholic mixtures. This generates fire and explosion hazard. 

Formula: HCN
Molecular mass: 27.03
Boiling point: 26°C
Melting point: -13°C
Relative density (water = 1): 0.69 (liquid)
Solubility in water: miscible
Vapour pressure, kPa at 20°C: 82.6
Relative vapour density (air = 1): 0.94
Flash point: -18°C c.c.
Auto-ignition temperature: 538°C
Explosive limits, vol% in air: 5.6-40.0
Octanol/water partition coefficient as log Pow: -0.25  


EXPOSURE & HEALTH EFFECTS

Routes of exposure
The substance can be absorbed into the body by inhalation, through the skin and by ingestion. 

Effects of short-term exposure
The substance is irritating to the eyes and respiratory tract. The substance may be irritating to the skin. The substance may cause effects on the cellular respiration. This may result in convulsions and unconsciousness. Exposure could cause death. Medical observation is indicated. See Notes. 

Inhalation risk
A harmful contamination of the air will be reached very quickly on evaporation of this substance at 20°C. 

Effects of long-term or repeated exposure
The substance may have effects on the thyroid. 


OCCUPATIONAL EXPOSURE LIMITS
TLV: (ceiling value): 4.7 ppm as STEL; (skin).
EU-OEL: 1 mg/m3, 0.9 ppm as TWA; 5 mg/m3, 4.5 ppm as STEL; (skin) 

ENVIRONMENT
The substance is very toxic to aquatic organisms. 

NOTES
The occupational exposure limit value should not be exceeded during any part of the working exposure.
Specific treatment is necessary in case of poisoning with this substance; the appropriate means with instructions must be available.
Isolate contaminated clothing by sealing in a bag or other container.
The odour warning when the exposure limit value is exceeded is insufficient.
The recommendations on this Card also apply to hydrogen cyanide, stabilized, absorbed in a porous inert material.
Other UN numbers: 1613, Hydrogen cyanide, aqueous solution, not more than 20% hydrogen cyanide; 1614, Hydrogen cyanide, stabilized, containing less than 3% water and absorbed in a porous inert material; 3294, Hydrogen cyanide, solution in alcohol with not more than 45% hydrogen cyanide.
Never work alone in an area if hydrogen cyanide exposure is possible.
Depending on the degree of exposure, periodic medical examination is suggested. 

ADDITIONAL INFORMATION
CLP00 : H300; H310; H330; H400; H410.
France : Valeurs limites réglementaires contraignantes : VLEP-8h = 2ppm ; VLCT = 10ppm.  EC Classification
 

All rights reserved. The published material is being distributed without warranty of any kind, either expressed or implied. Neither ILO nor WHO nor the European Commission shall be responsible for the interpretation and use of the information contained in this material.
    See Also:
       Toxicological Abbreviations