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Chemical Datasheet

POTASSIUM, METAL ALLOYS

4.3 - Dangerous when wet

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 7440-09-7
  • 1420
  • Dangerous When Wet
none
NIOSH Pocket Guide International Chem Safety Card
none
  • POTASSIUM
NFPA 704
Diamond Hazard Value Description
3
3 2
W
Blue Health 3 Can cause serious or permanent injury.
Red Flammability 3 Can be ignited under almost all ambient temperature conditions.
Yellow Instability 2 Readily undergoes violent chemical changes at elevated temperatures and pressures.
White Special W Reacts violently or explosively with water.
(NFPA, 2010)
General Description
Potassium, metal alloys is potassium mixed with some other metal, usually sodium. It is a liquid under normal conditions. It reacts vigorously with water to form potassium hydroxide, a corrosive material and hydrogen, a flammable gas. The heat from this reaction may be sufficient to ignite the hydrogen. Potassium alloy may ignite spontaneously in contact with air. Once ignited, potassium burns quite violently. It is used as a heat exchange fluid.

Hazards

Reactivity Alerts
Air & Water Reactions
Reacts vigorously with oxygen. Reacts vigorously with water even at less than 100°C [Merck, 11th ed., 1989]. Water (caustic solution, H2) The oxidation of potassium in air is so rapid that the heat generated by the reaction melts and ignites the metal. This is particularly the case when pressure is applied at ordinary temperatures [Sidgwick 1. 1950]. Potassium burns in moist air at room temperature [Mellor 2:468. 1946-47]. The higher oxides of potassium, formed in air, react explosively with pure potassium, sodium, sodium-potassium alloys, and organic matter [Mellor 2, Supp. 3:1559. 1963].
Fire Hazard
Excerpt from 138 Polymerizable warning [Substances - Water-Reactive (Emitting Flammable Gases)]:

Produce flammable gases on contact with water. May ignite on contact with water or moist air. Some react vigorously or explosively on contact with water. May be ignited by heat, sparks or flames. May re-ignite after fire is extinguished. Some are transported in highly flammable liquids. Runoff may create fire or explosion hazard. (ERG, 2020)
Health Hazard
Excerpt from 138 Polymerizable warning [Substances - Water-Reactive (Emitting Flammable Gases)]:

Inhalation or contact with vapors, substance or decomposition products may cause severe injury or death. May produce corrosive solutions on contact with water. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause environmental contamination. (ERG, 2020)
Reactivity Profile
Boron trifluoride reacts with incandescence when heated with alkali metals or alkaline earth metals except magnesium [Merck 11th ed. 1989]. Maleic anhydride decomposes explosively in the presence of alkali metals [Chemical Safety Data Sheet SD-88. (96)]; [Chem. Haz. Info. Series C-71. 1960]. Sodium peroxide oxidizes antimony, arsenic, copper, potassium, tin, and zinc with incandescence [Mellor 2:490-93. 1946-47]. Alkali metal hydroxides, acids, anhydrous chlorides of iron, tin, and aluminum, pure oxides of iron and aluminum, and metallic potassium are some of the catalysts that may cause ethylene oxide to rearrange and polymerize, liberating heat [J. Soc. Chem. Ind. 68:179. 1949]. Explosions occur, although infrequently, from the combination of ethylene oxide and alcohols or mercaptans [Chem. Eng. News 20:1318. 1942]. A mixture of potassium and any of the following metallic halides produces a strong explosion on impact: aluminum chloride, aluminum fluoride, ammonium fluorocuprate, antimony tribromide, antimony trichloride, antimony triiodide, cadmium bromide, cadmium chloride, cadmium iodide, chromium tetrachloride, cupric bromide, cupric chloride, cuprous bromide cuprous chloride, cuprous iodide, manganese chloride, mercuric bromide, mercuric chloride, mercuric fluoride, mercuric iodide, mercurous chloride, nickel bromide, nickel chloride, nickel iodide, silicon tetrachloride, silver fluoride, stannic chloride, stannic iodide (with silver), stannous chloride, sulfur dibromide, thallous bromide, vanadium pentachloride, zinc bromide, zinc chloride, and zinc iodide [Mellor 2, Supp. 3:1571. 1963]. A mixture of potassium and any of the following compounds produces a weak explosion on impact: ammonium bromide, ammonium iodide, cadmium fluoride, chromium trifluoride, manganous bromide, manganous iodide, nickel fluoride, potassium chlorocuprate, silver chloride, silver iodide, strontium iodide, thallous chloride, and zinc fluoride [Mellor 2, Supp. 3:1571. 1963]. A mixture of potassium and any of the following compounds may explode on impact: boric acid, copper oxychloride, lead oxychloride, lead peroxide, lead sulfate, silver iodate, sodium iodate, and vanadium oxychloride [Mellor 2, Supp. 3:1571. 1963]. A mixture of potassium with any of the following compounds produces a very violent explosion on impact: boron tribromide, carbon tetrachloride, cobaltous bromide, cobaltous chloride, ferric bromide, ferric chloride, ferrous bromide, ferrous chloride, ferrous iodide, phosphorus pentachloride, phosphorus tribromide, and sulfur dichloride [Mellor 2, Supp. 3:1571. 1963]. Mixture of solid potassium and carbon dioxide(as dry ice) explodes when subjected to shock [Mellor 2, Supp. 3:1568. 1963]. Potassium and its alloys form explosive mixtures with chlorinated hydrocarbons [Chem. Eng. News 26:2604. 1948]. Ethylene oxide is dangerously reactive with metallic potassium [Chemical Safety Data Sheet SD-38:11. 1951]. Potassium in contact with the following oxides causes an explosive reaction: potassium ozonide, potassium peroxide, or potassium superoxide [Mellor 2, Supp. 3:1577. 1963].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
Excerpt from 138 Polymerizable warning [Substances - Water-Reactive (Emitting Flammable Gases)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)
Firefighting
Excerpt from 138 Polymerizable warning [Substances - Water-Reactive (Emitting Flammable Gases)]:

DO NOT USE WATER OR FOAM.

SMALL FIRE: Dry chemical, soda ash, lime or sand.

LARGE FIRE: DRY sand, dry chemical, soda ash or lime or withdraw from area and let fire burn. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING METALS OR POWDERS (ALUMINUM, LITHIUM, MAGNESIUM, ETC.): Use dry chemical, DRY sand, sodium chloride powder, graphite powder or class D extinguishers; in addition, for Lithium you may use Lith-X® powder or copper powder. Also, see 170 Polymerizable warning.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2020)
Non-Fire Response
Excerpt from 138 Polymerizable warning [Substances - Water-Reactive (Emitting Flammable Gases)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. 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 GET WATER on spilled substance or inside containers.

SMALL SPILL: Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Dike for later disposal; do not apply water unless directed to do so.

POWDER SPILL: Cover powder spill with plastic sheet or tarp to minimize spreading and keep powder dry. DO NOT CLEAN-UP OR DISPOSE OF, EXCEPT UNDER SUPERVISION OF A SPECIALIST. (ERG, 2020)
Protective Clothing
Excerpt from ERG Guide 138 [Substances - Water-Reactive (Emitting Flammable Gases)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2020)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
Excerpt from 138 Polymerizable warning [Substances - Water-Reactive (Emitting Flammable Gases)]:

Call 911 or emergency medical service. Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air if it can be done safely. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, wipe from skin immediately; flush skin or eyes with running water for at least 20 minutes. Keep victim calm and warm. (ERG, 2020)

Physical Properties

Chemical Formula:
  • K
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: data unavailable
Vapor Pressure: data unavailable
Vapor Density (Relative to Air): data unavailable
Specific Gravity: data unavailable
Boiling Point: data unavailable
Molecular Weight: data unavailable
Water Solubility: data unavailable
Ionization Energy/Potential: data unavailable
IDLH: data unavailable

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Potassium (7440-09-7) 2.3 mg/m3 25 mg/m3 150 mg/m3
(DOE, 2018)

Regulatory Information

EPA Consolidated List of Lists

No regulatory information available.

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names