Potassium cyanide

Formula
KCN
Structure
Description
White powder or lumps, odorless when dry, slight odor of HCN when damp, HCN smells like bitter almonds, deliquescent.
Uses
Used for gold and silver extraction, in chemical analysis, to make other chemicals, and as an insecticide.

Registry Numbers and Inventories.
CAS
151-50-8
EC (EINECS/ELINCS)
205-792-3
EC Index Number
006-007-00-5
EC Class
very toxic, dangerous for the environment
R 26/27/28 32 50/53
S 7 28 29 45 60 61
RTECS
TS8750000
RTECS class
Mutagen; Reproductive Effector; Human Data
UN (DOT)
1680
Merck
12,7789
Beilstein/Gmelin
9954 (G)
RCRA
P098
EPA OPP
599600
Swiss Giftliste 1
G-1743
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
CKN
Formula mass
65.12
Melting point, °C
634
Boiling point, °C
1625
Decomposition point, °C
200 - 260
Vapor density (air=1)
2.2
Density
1.56 g/cm3 (25 C)
Solubility in water
237 g/L (25 C)
Dielectric constant
6.15
Thermal expansion
0.000049/K
Heat of fusion
14.6 kJ/mol

Hazards and Protection.
Storage
Store in a tightly closed container. Keep from contact with oxidizing materials. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from acids.
D1A D2B E
Handling
Wash thoroughly after handling. Use with adequate ventilation. Minimize dust generation and accumulation. Do not get in eyes, on skin, or on clothing. Do not ingest or inhale. Wash clothing before reuse.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Decontaminate trace cyanide in the spill area with a strong sodium or calcium hypochlorite solution and flush waste to a holding area for potassium removal.
Stability
Very stable when dry. Moisture will cause slow decomposition, releasing poisonous hydrogen cyanide gas.
Incompatibilities
Strong acids and strong oxidizers. Reacts with acids to liberate toxic and flammable hydrogen cyanide gas. Water or weak alkaline solutions can produce dangerous amounts of hydrogen cyanide in confined areas. Can react with carbon dioxide in ordinary air to form hydrogen cyanide gas.
Decomposition
Emits toxic fumes of cyanide and oxides of nitrogen when heated to decomposition.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water. Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Extinguishing media: Substance is noncombustible; use agent most appropriate to extinguish surrounding fire. Do NOT use carbon dioxide.
Fire potential
Nonflammable.
Hazards
Contact with acid releases highly flammable hydrogen cyanide gas. Moisture may cause this material to volatilize as hydrogen cyanide. When heated to decomposition, it emits very toxic fumes of cyanide and nitrogen oxides. Reacts with acids to produce hydrogen cyanide gas. Reacts with strong oxidizers such as nitrates and chlorates, nitrogen trichloride; perchloryl fluoride; sodium nitrate; acids; alkaloids; chloral hydrate; iodine. Avoid contact with acids.
Combustion products
When heated to decompose it emits very toxic fumes of cyanide and oxides of nitrogen.
Health
3
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure limit(s)
OSHA PEL: TWA 5 mg/m3 NIOSH REL: C 5 mg/m3 (4.7 ppm) 10-minute *Note: PEL and REL also apply to other cyanides (as CN) except Hydrogen cyanide. NIOSH IDLH: 25 mg/m3 (as CN)
Poison_Class
1
Exposure effects
In most cases, cyanide poisoning causes a deceptively healthy pink to red skin color. However, if a physical injury or lack of oxygen is involved, the skin color may be bluish. Reddening of the eyes and pupil dilation are symptoms of cyanide poisoning. Cyanosis (blue discoloration of the skin) tends to be associated with severe cyanide poisonings. Prolonged or repeated skin exposure may cause a cyanide rash and nasal sores.
   Ingestion
Highly Toxic! Corrosive to the gastro-intestinal tract with burning in the mouth and esophagus, and abdominal pain. Larger doses may produce sudden loss of consciousness and prompt death from respiratory arrest. Smaller but still lethal doses may prolong the illness for one or more hours. Bitter almonds odor may be noted on the breath or vomitus. Other symptoms may be similar to those noted for inhalation exposure.
   Inhalation
Corrosive to the respiratory tract. The substance inhibits cellular respiration and may cause blood, central nervous system, and thyroid changes. May cause headache, weakness, dizziness, labored breathing nausea and vomiting, which can be followed by weak and irregular heart beat, unconsciousness, convulsions, coma and death.
   Skin
Corrosive. May cause severe pain and skin burns. Solutions are corrosive to the skin and eyes, and may cause deep ulcers which heal slowly. May be absorbed through the skin, with symptoms similar to those noted for inhalation.
   Eyes
Corrosive. Symptoms may include redness, pain, blurred vision, and eye damage.

First aid
 
   Ingestion
N CASE OF CYANIDE POISONING, start first aid treatment immediately, then get medical attention. A cyanide antidote kit (amyl nitrite, sodium nitrite and sodium thiosulfate) should be available in any cyanide work area. Actions to be taken in case of cyanide poisoning should be planned and practiced before beginning work with cyanides. Oxygen and amyl nitrite can be given by a first responder before medical help arrives. Allow victim to inhale amyl nitrite for 15-30 seconds per minute until sodium nitrite and sodium thiosulfate can be administered intravenously (see Note to Physician). A new amyl nitrite ampule should be used every 3 minutes. If conscious but symptoms (nausea, difficult breathing, dizziness, etc.) are evident, give oxygen. If consciousness is impaired (non-responsiveness, slurred speech, confusion, drowsiness) or the patient is unconscious but breathing, give oxygen and amyl nitrite by means of a respirator. If not breathing, give oxygen and amyl nitrite immediately by means of a positive pressure respirator (artificial respiration). Get medical aid immediately. SPEED IS ESSENTIAL. A DOCTOR MUST BE NOTIFIED AT ONCE. Do not give anything by mouth. Treat patient as for inhalation.
   Inhalation
Remove from exposure to fresh air immediately. DO NOT use mouth-to-mouth respiration. Keep warm and at rest. Administer oxygen. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask. SPEED IS ESSENTIAL, OBTAIN MEDICAL AID IMMEDIATELY. See Ingestion.
   Skin
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Discard contaminated clothing in a manner which limits further exposure. SPEEDY ACTION IS CRITICAL! Treat patient as for inhalation. See Ingestion.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Treat patient as for inhalation. See Ingestion.

Transport.
UN number
1680
Response guide
Hazard class
6.1
PRTC
T
Packing Group
I
 
USCG CHRIS Code
PTC
 
HS Code
2837 19 00
 
Std. Transport #
4923226 4923225