NFPA 491

Abstract

This guide had its beginnings in an extensive literature survey conducted by the late George W. Jones of the US. Bureau of Mines during his work with NFPA and American Chemical Society Technical Committees. The current 1997 edition contains approximately 3550 documented reactions. Readers are encouraged to submit documentation of additional reactions to be considered for inclusion in this guide. <br> The purpose of the guide is to provide users of chemicals with a compilation of recorded experience with chemical reactions that have potential for danger. Thus, the abstracts presented here range from reactions that produce incandescence or flame at moderate or slightly elevated temperatures to those that produce explosions or detonations. However, when presenting such a large compilation of data as is presented in this guide, one must be aware of some possible limitations and considerations when using the data. Since some of the information was obtained from very old references, its validity may be questioned; many of the reported hazardous reactions may have been due to impurities or contaminants in the materials involved. At the same time, the user should be cautioned that the absence of a reaction from this listing in no way implies that combinations of materials may be mixed with impunity with or without heating. Similarly, the comments that may be appended to particular reactions regarding their violence should be tempered by consideration of quantities involved, temperatures, confinement, and many other factors. <br> For convenience, many potentially hazardous reaction mixtures have been brought together into groups. For example, the reactions of mixtures of inorganic perchlorates with many fuels can be quite violent. This association of different reactants in the same group should not be taken, however, as an indication that all such related compounds will react with equal rates or ease with a given fuel, that the violence will be equivalent in every case, or that potential contaminants such as moisture will have the same effect. The reader is warned that trace quantities of contaminants acting as catalysts may have a profound effect on the course and rate of the reaction. Unless there is unusual reactivity with air, oxygen, or water, the usual combustion reactions involving these oxidants have not been included for all possible fuel substances. Finally, any mixture of oxidizing and reducing agents should be suspected of being able to undergo a hazardous reaction.