Pyrophoric solids

A pyrophoric solid is a solid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air. 

A pyrophoric solid is classified in a single category for this class using test N.2 in Part III, sub-section 33.3.1.4 of the UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria according to the following table  

1 The solid ignites within 5 minutes of coming into contact with air. 

NOTE For classification tests on solid substances or mixtures, the tests should be performed on the 

General and specific considerations concerning labelling requirements are provided in Hazard communication Labelling (Chapter 1.4). Annex 2 contains summary tables about classification and labelling. Annex 3 contains examples of precautionary statements and pictograms which can be used where allowed by the competent authority. 

A positive result is obtained in a test using a 25 mm sample cube at 140 °C. 

Self-heating in large quantities, may catch fire 

12 Substances which, on Contact with Water, Emit Flammable Cases Hazard category 1  

Any substance which reacts vigorously with water at ambient temperatures and demonstrates generally a tendency for the gas produced to ignite spontaneously, or which reacts readily with water at ambient temperatures such that the rate of evolution of flammable gas is equal to or greater than 10 L kg of substance over any one minute. 

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Dangerous materials may require special equipment. Chlorination with gaseous chlorine requires quite expensive storage facilities. Chlorination with chlorine, thionyl chloride, sulphuryl chloride, phosphorus oxychloride, phosphorus trichloride, or phosphorus pentachloride, all of which are fairly hazardous, requires off-gas treatment. Some of these reactants can be recycled. Pyrophoric solids such as hydrogenation catalysts, anhydrous aluminium trichloride for Friedel-Crafts reactions, or hydrides used as reducing agents should usually be handled using special facilities. Therefore, all of the above proce.sses are usually carried out in dedicated plants. 

Leleu, Cahiers, 1977, (88), 367 As usually prepared, it is a pyrophoric solid. 

Attempts to recover the complex from solutions in solvents other than diglyme led to the formation of pyrophoric solids. 

Potassium hydride, 35% by weight in mineral oil, was purchased from Aldrich Chemical Company, Inc., and washed with dry pentane prior to use. Note that potassium hydride is a pyrophoric solid and must be handled with extreme care. 

Zinc Hydrezide. NHNHZn, H2N2Zn mw 95.42 N 2936% pyrophoric solid. Prepn is by reacting w (cautiously) with Zn nitride. The... 

PYROPHORIC MATERIAL. Any liquid or solid that will ignite spontaneously in air at about 130F (54.4C). Titanium dichloride and phosphorus are examples of pyrophoric solids tnbutylaluminum and related compounds are pyrophoric liquids. Sodium, butyLithium, and lithium hydride are spontaneously flammable in moist air because they react exothermically with water, Such materials must be stored in an atmosphere of inert gas or under kerosene. Some alloys (barium, misch metal) are called pyrophoric because they spark when slight friclion is applied. 

Cp V (/i-HbBH, CpjVClj/NaBH Dark-violet pyrophoric solid... 

Phenyllithium lO Colorless pyrophoric solid used in Grignard-type reactions to attach a phenyl group... 

Alkali metals supported by nanoporous carbons were proposed by Stevens et al. as non-pyrophoric solid-base catalysts with high activity in 1-butene isomerization and side-chain alkylation of toluene with propene [32, 33]. 

Cp(r, -C.H.)Nb(M-H)AlEt,], "niobocene dimer/EtfAl Pyrophoric solid. 

Attempts to recover [K(diglyme)3][Nb(CO)6] from its solutions in solvents other than diglyme invariably lead to the formation of pyrophoric solids. Similarly, it has been reported that the only previously known compound containing this cation, [K(diglyme)3][Mo(CO)5l], cannot be recrystallized from... 

The classification procedure for pyrophoric solids need not be applied when experience in production or handling shows that the substance or mixture does not ignite spontaneously on coming into contact with air at normal temperatures (i.e. the substance or mixture is known to be stable at room temperature for prolonged periods of time (days)). 

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