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NIOSH

HYDROGEN CYANIDE, LIQUEFIED

ICSC: 0492

Hydrocyanic acid
Prussic acid
Formonitrile
HCN
Molecular mass: 27.03
(liquefied)
ICSC # 0492 		CAS # 74-90-8
RTECS # MW6825000
UN # 1051
EC # 006-006-00-X
July 05, 2003 Validated

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. Unconsciousness. Death.
Ventilation, local exhaust, or breathing protection.
Fresh air, rest. Half-upright position. No mouth-to-mouth artificial respiration. Administer oxygen by trained personnel. 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 VAPOUR WILL BE ABSORBED! Redness. (See Inhalation).
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 take to a doctor.
•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. Administer oxygen by trained personnel. Refer for medical attention. See Notes.

SPILLAGE DISPOSAL

STORAGE

PACKAGING & LABELLING

Evacuate danger area immediately! Consult an expert! Ventilation. Remove all ignition sources. Absorb remaining liquid in sand or inert absorbent and remove to safe place. NEVER direct water jet on liquid. Do NOT let this chemical enter the environment. Gas-tight chemical protection suit including self-contained breathing apparatus.
Fireproof. Separated from food and feedstuffs . Cool. Store only if stabilized.

Marine pollutant.
F+ symbol
T+ symbol
N symbol
R: 12-26-50/53
S: 1/2-7/9-16-36/37-38-45-60-61
UN Hazard Class: 6.1
UN Subsidiary Risks: 3
UN Packing Group: I
ICSC: 0492 Prepared in the context of cooperation between the International Programme on Chemical Safety & the Commission of the European Communities (C) IPCS CEC 1994. No modifications to the International version have been made except to add the OSHA PELs, NIOSH RELs and NIOSH IDLH values.

HYDROGEN CYANIDE, LIQUEFIED

ICSC: 0492

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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 base(s) , over 2% water, or if not chemically stabilized, with fire or explosion hazard. On combustion, forms toxic and corrosive gasesincludingnitrogen oxides. The solution in water is a weak acid. Reacts violently with oxidants , hydrogen chloride in alcoholic mixtures, causing fire and explosion hazard.

OCCUPATIONAL EXPOSURE LIMITS:
TLV: 4.7 ppm; (Ceiling value); (skin); (ACGIH 2003).
MAK: 1.9 ppm, 2.1 mg/m3; H;
Peak limitation category: II(2); Pregnancy risk group: C;
(DFG 2002).
OSHA PEL†: TWA 10 ppm (11 mg/m3) skin
NIOSH REL: ST 4.7 ppm (5 mg/m3) skin
NIOSH IDLH: 50 ppm See: 74908


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 the respiratory tract . The substance may cause effects on the cellular respiration , resulting in convulsions and unconsciousness . Exposure may result in death. Medical observation is indicated. See Notes.

EFFECTS OF LONG-TERM OR REPEATED EXPOSURE:
The substance may have effects on the thyroid .

PHYSICAL
PROPERTIES

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

ENVIRONMENTAL
DATA

The substance is very toxic to aquatic organisms.

N O T E S

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 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.
Transport Emergency Card: TEC (R)-61S1051

NFPA Code: H4; F4; R2;

ADDITIONAL INFORMATION



ICSC: 0492 HYDROGEN CYANIDE, LIQUEFIED
(C) IPCS, CEC, 1994
IMPORTANT LEGAL NOTICE: Neither NIOSH, the CEC or the IPCS nor any person acting on behalf of NIOSH, the CEC or the IPCS is responsible for the use which might be made of this information. This card contains the collective views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use. The only modifications made to produce the U.S. version is inclusion of the OSHA PELs, NIOSH RELs and NIOSH IDLH values.
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