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HYDROGEN CYANIDE, LIQUEFIED
(liquefied)
ICSC: 0492
Peer-Review Status: 05.07.2003 Validated
Hydrocyanic acid
Prussic acid
Formonitrile 
CAS #: 74-90-8 RTECS #: MW6825000
UN #: 1051
EC #: 006-006-00-X
EINECS #: 200-821-6
    Formula: HCN
Molecular mass: 27.03

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Extremely flammable. Gives off irritating or toxic fumes (or gases) in a fire.  NO open flames, NO sparks and NO smoking.  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. 
EXPLOSION Gas/air mixtures are explosive.  Closed system, ventilation, explosion-proof electrical equipment and lighting.  In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position. 
 
EXPOSURE   AVOID ALL CONTACT!  IN ALL CASES CONSULT A DOCTOR! 
Inhalation Confusion. Drowsiness. Headache. Nausea. Convulsions. Shortness of breath. Unconciousness. 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
PACKAGING & 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.  Marine pollutant. 
EC Classification
Symbol: F+, T+, N; R: 12-26-50/53; S: (1/2)-7/9-16-36/37-38-45-60-61 
UN Classification
UN Hazard Class: 6.1; UN Subsidiary Risks: 3; UN Pack Group: I 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-61S1051.
NFPA Code: H4; F4; R2. 
Fireproof. Separated from food and feedstuffs. Cool. Store only if stabilized. 

IMPORTANT DATA
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. 

Occupational exposure limits
TLV: 4.7ppm (ceiling value); (skin); (ACGIH 2003).
MAK: 1.9 ppm, 2.1 mg/m³; Peak limitation category: II(2); Pregnancy risk group: C; Skin absorption (H); (DFG 2002). 

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

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

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. 

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


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
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  
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
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.


    See Also:
       Toxicological Abbreviations