Pyrophoric solids and liquids

Pentaborane is a nonmetallic, colorless liquid with a pungent odor. It decomposes at 300°F, if it has not already ignited, and will ignite spontaneously in air if 

A bag of charcoal, an ORM-D material, that may undergo spontaneous heating upon contact with water. If the heat is confined, combustion may occur. 

Aluminum alkyls are colorless liquids or solids. They are pyrophoric and may ignite spontaneously in air. They are often in solution with hydrocarbon solvents. Aluminum alkyls are pyrophoric materials in a flammable solvent. The vapors are heavier than air, water-reactive, and corrosive. Decomposition begins at 350°F. The four-digit UN identification number is 3051. The NFPA 704 designation is health 3, flammability 4, and reactivity 3. The white space at the bottom of the diamond has a W with a slash through it, indicating water reactivity. They are used as catalysts in polymerization reactions. 

Potassium sulfide, K2S, is a binary salt. It is a red or yeUow-red crystalline mass or fused solid. It is deliquescent in air, which means it absorbs water from the air, and it is also soluble in water. Potassium sulfide is a dangerous fire risk and may ignite spontaneously. It is explosive in the form of dust and powder. It decomposes at 1562°F and melts at 1674°F. The specific gravity is 1.74, which is heavier than air. The four-digit UN identification number is 1382. The NFPA 704 designation is health 3, flammability 1, and reactivity 0. Potassium sulfide is used primarily in analytical chemistry and medicine. 

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