Sodium-potassium alloy

A low-melting alloy of Na and K. Its toxicity is due to either Na or K alone. Corrosive to the eyes, skin, and mucous membranes. Upon contact with moisture it reacts violently to evolve H2; much heat; and a highly caustic residue of NaOH or KOH. Oxidation forms Na2O and K2O, which are powerful caustics.A dangerous fire and explosion hazard. Violent or explosive reaction with O2, water, moisture, steam, halogens, oxidizers, acids or acid fumes, giving off much heat, hydrogen, toxic and corrosive fumes, often spattering either red-hot particles or actually flaming particles. A severe explosion hazard, will react explosively under the appropriate conditions with moisture, acids, acid fumes, solid CO2, carbon disulfide, halocarbons (e.g., CH3Cl, carbon tetrachloride, chloroform, bromoform, 1,1,1-trichloroethane, 1,1,2-trichlorotrifluoroethane, tetrachloroethane, CH2Cl2, CH2I2), ammonium sulfate + NH4 + NO3, HgO, metal halides (e.g., silver halides, zinc chloride, iron(III) chloride), metal oxides (e.g., silver oxide, mercury oxide), nitrogen-containing explosives (e.g., ammonium nitrate, ammonium sulfate, picric acid, nitrobenzene), oxalyl bromide, oxalyl chloride, pentachloroethane, K oxides, KO2, Si, NaHCO3, polytetrafluoroethylene. Reacts vigorously with oxidizing materials.To fight fire, use G-1 powder, dry sodium chloride, dry sodium carbonate, dry calcium carbonate, dry sand, resin-coated sodium chloride, or dry soda ash. Never use water, graphite, carbon dioxide, halocarbons, or foam.Dangerous; when heated it emits highly toxic fumes of Na2O and K2O. Used as a liquid coolant for nuclear reactor cores. See also SODIUM and POTASSIUM.