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Chemical Datasheet

HYDROGEN CYANIDE, ANHYDROUS, STABILIZED

6.1 - Poison Inhalation Hazard 3 - Flammable liquid

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 74-90-8   (HYDROGEN CYANIDE)
  • 1051
  • Poison Inhalation Hazard
  • Flammable Liquid
none
NIOSH Pocket Guide International Chem Safety Card
Hydrogen cyanide
  • HYDROGEN CYANIDE, LIQUEFIED
NFPA 704
Diamond Hazard Value Description
4
4 1
Blue Health 4 Can be lethal.
Red Flammability 4 Burns readily. Rapidly or completely vaporizes at atmospheric pressure and normal ambient temperature.
Yellow Instability 1 Normally stable but can become unstable at elevated temperatures and pressures.
White Special
(NFPA, 2010)
General Description
Very volatile colorless or pale-blue liquid or gas (above 78°F) with a bitter, almond-like odor. Often used as a 96% solution in water. (NIOSH, 2016) A deadly human poison by all routes.

Hazards

Reactivity Alerts
Air & Water Reactions
Highly flammable. Soluble in water
Fire Hazard
Excerpt from ERG Guide 117 [Gases - Toxic - Flammable (Extreme Hazard)]:

These materials are extremely flammable. May form explosive mixtures with air. May be ignited by heat, sparks or flames. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Runoff may create fire or explosion hazard. Cylinders exposed to fire may vent and release toxic and flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. (ERG, 2016)
Health Hazard
Excerpt from ERG Guide 117 [Gases - Toxic - Flammable (Extreme Hazard)]:

TOXIC; Extremely Hazardous. May be fatal if inhaled or absorbed through skin. Initial odor may be irritating or foul and may deaden your sense of smell. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution. (ERG, 2016)
Reactivity Profile
ANHYDROUS HYDROGEN CYANIDE presents a severe explosion hazard when exposed to oxidizing agents. Boils at 26.5°C (79.8°F). The vapors form explosive mixtures with air. May polymerize explosively at elevated temperature (50-60°C) or in the presence of traces of alkali [Wohler, L. et al., Chem. Ztg., 1926, 50, p. 761, 781]. In the absence of a stabilizer (such as phosphoric acid), may undergo explosively rapid spontaneous (autocatalytic) polymerization leading to a fire. The reaction is autocatalytic because of ammonia formation. [Bond, J., Loss Prev. Bull., 1991, 101, p.3]. Dissolves in water to give weakly acidic solutions. Reacts violently with acetaldehyde. During the preparation of imidoester hydrochlorides, hydrogen chloride was rapidly passed over alcoholic hydrogen cyanide. An explosion ensued, even with cooling of the process [J. Org. Chem., 1955, 20, 1573].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below.

Response Recommendations

Isolation and Evacuation
Excerpt from ERG Guide 117 [Gases - Toxic - Flammable (Extreme Hazard)]:

As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1051 datasheet.

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. (ERG, 2016)
Firefighting
Excerpt from ERG Guide 117 [Gases - Toxic - Flammable (Extreme Hazard)]:

DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam.

LARGE FIRE: Water spray, fog or regular foam. Move containers from fire area if you can do it without risk. Damaged cylinders should be handled only by specialists.

FIRE INVOLVING TANKS: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)
Non-Fire Response
Excerpt from ERG Guide 117 [Gases - Toxic - Flammable (Extreme Hazard)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Fully encapsulating, vapor-protective clothing should be worn for spills and leaks with no fire. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Isolate area until gas has dispersed. Consider igniting spill or leak to eliminate toxic gas concerns. (ERG, 2016)
Protective Clothing
Skin: Wear appropriate personal protective clothing to prevent skin contact.

Eyes: Wear appropriate eye protection to prevent eye contact.

Wash skin: The worker should immediately wash the skin when it becomes contaminated.

Remove: Work clothing that becomes wet should be immediately removed due to its flammability hazard(i.e. for liquids with flash point < 100°F)

Change: No recommendation is made specifying the need for the worker to change clothing after the work shift.

Provide: Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection. Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2016)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP BR RC TK RF
HCN (Hydrogen cyanide) (>95%, gas) 74-90-8 Vapor 30 >480 >480 >480 >480 >480
HCN (Hydrogen cyanide) (>95%, liquid, 21° C) 74-90-8 Liquid 105 105 >480 105
Hydrocyanic acid (>95%, gas) 74-90-8 Vapor 30 >480 >480 >480 >480 >480
Hydrocyanic acid (>95%, liquid, 21° C) 74-90-8 Liquid 105 105 >480 105
Hydrogen cyanide (>95%, gas) 74-90-8 Vapor 30 >480 >480 >480 >480 >480
Hydrogen cyanide (>95%, liquid, 21° C) 74-90-8 Liquid 105 105 >480 105
> indicates greater than.
A blank cell indicates the fabric has not been tested. The fabric may or may not offer barrier.

Special Warnings from DuPont

  1. Serged and bound seams are degraded by some hazardous liquid chemicals, such as strong acids, and should not be worn when these chemicals are present.
  2. CAUTION: This information is based upon technical data that DuPont believes to be reliable. It is subject to revision as additional knowledge and experience are gained. DuPont makes no guarantee of results and assumes no obligation or liability...

(DuPont, 2018)

First Aid
Eye: If this chemical contacts the eyes, immediately wash the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Contact lenses should not be worn when working with this chemical.

Skin: If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform mouth-to-mouth resuscitation. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2016)

Physical Properties

Chemical Formula:
  • CHN
Flash Point: 0 ° F (96%) (NIOSH, 2016)
Lower Explosive Limit (LEL): 5.6 % (NIOSH, 2016)
Upper Explosive Limit (UEL): 40 % (NIOSH, 2016)
Autoignition Temperature: data unavailable
Melting Point: 7 ° F (96%) (NIOSH, 2016)
Vapor Pressure: 630 mm Hg (NIOSH, 2016)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 0.69 (NIOSH, 2016)
Boiling Point: 78 ° F at 760 mm Hg (96%) (NIOSH, 2016)
Molecular Weight: 27 (NIOSH, 2016)
Water Solubility: Miscible (NIOSH, 2016)
Ionization Potential: 13.60 eV (NIOSH, 2016)
IDLH: 50 ppm (NIOSH, 2016)

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for Hydrogen cyanide (74-90-8)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes 2.5 ppm 17 ppm 27 ppm
30 minutes 2.5 ppm 10 ppm 21 ppm
60 minutes 2 ppm 7.1 ppm 15 ppm
4 hours 1.3 ppm 3.5 ppm 8.6 ppm
8 hours 1 ppm 2.5 ppm 6.6 ppm
(NAC/NRC, 2017)

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Hydrogen Cyanide (74-90-8) NA 10 ppm 25 ppm
NA = not appropriate.
(AIHA, 2016)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Hydrogen cyanide; (Hydrocyanic acid) (74-90-8) 2 ppm 7.1 ppm 15 ppm LEL = 56000 ppm
(DOE, 2016)

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Cyanide Compounds N106 & 313
Hydrocyanic acid 74-90-8 100 pounds 10 pounds 10 pounds X P063 2500 pounds
Hydrogen cyanide 74-90-8 100 pounds 10 pounds 10 pounds 313 P063 2500 pounds

(EPA List of Lists, 2015)

DHS Chemical Facility Anti-Terrorism Standards (CFATS)

RELEASE THEFT SABOTAGE
Chemical of Interest CAS Number Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Hydrocyanic acid 74-90-8 1.00 % 2500 pounds toxic
Hydrogen cyanide; [Hydrocyanic acid] 74-90-8 4.67 % 15 pounds WME

(DHS, 2007)

OSHA Process Safety Management (PSM) Standard List

Chemical Name CAS Number Threshold Quantity (TQ)
Hydrogen Cyanide, Anhydrous 74-90-8 1000 pounds

(OSHA, 2011)

Alternate Chemical Names