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HYDROGEN CYANIDE, LIQUEFIEDICSC: 0492
July 2003
CAS #: 74-90-8Hydrocyanic acid
Prussic acid
Formonitrile
UN #: 1051
EINECS #: 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, 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 ACUTE HAZARDS FIRST AID
Inhalation Confusion. Drowsiness. Headache. Nausea. Convulsions. Shortness of breath. Unconsciousness. Death  Use ventilation, local exhaust or breathing protection.  Fresh air, rest. Half-upright position. No mouth-to-mouth artificial respiration. Administration of oxygen may be needed. Refer for medical attention. See Notes. 
Skin MAY BE ABSORBED! Further see Inhalation.  Protective gloves. Protective clothing.  Rinse skin with plenty of water or shower. Refer for medical attention . Wear protective gloves when administering first aid. 
Eyes MAY BE ABSORBED! Redness. See Inhalation.  Wear safety goggles 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. Do NOT induce vomiting. NO mouth-to-mouth artificial respiration. Administration of oxygen may be needed. Refer for medical attention . See Notes. 

SPILLAGE DISPOSAL CLASSIFICATION & LABELLING
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. Remove all ignition sources. 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

 

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

STORAGE
Fireproof. Separated from food and feedstuffs. Cool. Store only if stabilized. 
PACKAGING
Marine pollutant. 
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 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 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: 4.7 (ceiling) ppm as STEL; (skin).
MAK: 2.1 mg/m3, 1.9 ppm; peak limitation category: II(2); skin absorption (H); pregnancy risk group: C.
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.
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% of hydrogen cyanide; 1614, Hydrogen cyanide stabilized, absorbed in a porous inert material; 3294, Hydrogen cyanide solution in alcohol, not more than 45% of hydroge
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
  EC Classification
Symbol: F+, T+, N; R: 12-26-50/53; S: (1/2)-7/9-16-36/37-38-45-60-61 

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    See Also:
       Toxicological Abbreviations