HYDROCYANIC ACID, AQUEOUS SOLUTIONS, WITH MORE THAN 20% HYDROGEN CYANIDE
|CAS Number||UN/NA Number||DOT Hazard Label||USCG CHRIS Code|
|NIOSH Pocket Guide||International Chem Safety Card|
|Health||4||Can be lethal.|
|Flammability||4||Burns readily. Rapidly or completely vaporizes at atmospheric pressure and normal ambient temperature.|
|Instability||1||Normally stable but can become unstable at elevated temperatures and pressures.|
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)
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)
Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below. More info about absorbents, including situations to watch out for...
- Mineral-Based & Clay-Based Absorbents
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)
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)
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)
Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. (ERG, 2016)
|QS = Tychem 2000 SFR|
|QC = Tychem 2000|
|SL = Tychem 4000|
|C3 = Tychem 5000|
|TF = Tychem 6000|
|TP = Tychem 6000 FR|
|BR = Tychem 9000|
|RC = Tychem RESPONDER® CSM|
|TK = Tychem 10000|
|RF = Tychem 10000 FR|
|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|
A blank cell indicates the fabric has not been tested. The fabric may or may not offer barrier.
Special Warnings from DuPont
- 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.
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...
... in connection with this information. It is the user's responsibility to determine the level of toxicity and the proper personal protective equipment needed. The information set forth herein reflects laboratory performance of fabrics, not complete garments, under controlled conditions. It is intended for informational use by persons having technical skill for evaluation under their specific end-use conditions, at their own discretion and risk. Anyone intending to use this information should first verify that the garment selected is suitable for the intended use. In many cases, seams and closures have shorter breakthrough times and higher permeation rates than the fabric. Please contact DuPont for specific data. If fabric becomes torn, abraded or punctured, or if seams or closures fail, or if attached gloves, visors, etc. are damaged, end user should discontinue use of garment to avoid potential exposure to chemical. Since conditions of use are outside our control, we make no warranties, express or implied, including, without limitation, no warranties of merchantability or fitness for a particular use and assume no liability in connection with any use of this information. This information is not intended as a license to operate under or a recommendation to infringe any patent or technical information of DuPont or others covering any material or its use.
Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. Keep victim calm and warm. Keep victim under observation. Effects of contact or inhalation may be delayed. (ERG, 2016)
AEGLs (Acute Exposure Guideline Levels)
|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|
ERPGs (Emergency Response Planning Guidelines)
|Hydrogen Cyanide (74-90-8)||NA||10 ppm||25 ppm|
PACs (Protective Action Criteria)
|Hydrogen cyanide; (Hydrocyanic acid) (74-90-8)||2 ppm||7.1 ppm||15 ppm||LEL = 56000 ppm|
EPA Consolidated List of Lists
|Regulatory Name||CAS Number/
313 Category Code
|CERCLA RQ||EPCRA 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|
- "X" indicates that this is a second name for an EPCRA section 313 chemical already included on this consolidated list. May also indicate that the same chemical with the same CAS number appears on another list with a different chemical name.
- & indicates that no RQ is assigned to this generic or broad class, although the class is a CERCLA hazardous substance. See 50 Federal Register 13456 (April 4, 1985).
(EPA List of Lists, 2015)
DHS Chemical Facility Anti-Terrorism Standards (CFATS)
|Chemical of Interest||CAS Number||Min Conc||STQ||Security
|Hydrocyanic acid||74-90-8||1.00 %||2500 pounds||toxic|
|Hydrogen cyanide; [Hydrocyanic acid]||74-90-8||4.67 %||15 pounds||WME|
- WME = weapons of mass effect.
OSHA Process Safety Management (PSM) Standard List
|Chemical Name||CAS Number||Threshold Quantity (TQ)|
|Hydrogen Cyanide, Anhydrous||74-90-8||1000 pounds|
Alternate Chemical Names
- HYDROCYANIC ACID, AQUEOUS SOLUTIONS, WITH MORE THAN 20% HYDROGEN CYANIDE