I
in the Chemical laboratory Ediled by NORMAN V. STEERE, 140 Melbourne Ave., S:E. Minneapolis, Minn. 5541 4
XCXI. Manual of Hazardous Chemical Reactions* R. F. Schwab,? Safety a n d Loss Prevention Engineer, Allied Chemical Corporation, P.O. Box 1057R, Morristown, N.J. 07960
The Manual of Hazardous Chemicol Reactions (NFPA No. 491M) is a compilation of laboratory and plant incidents involving chemicals. The NFPA Committee an Hazardous Chemical Reactions collects the information from a variety of sources -periodicals, chemical literature, books, letters to the editor in prafessional periodicals such as Chemical and Engineering Neus,personal communications, industrywide and individual chemical company accident reports, government reports, and any others that we consider reliable sources. All the input is carefully reviewed by the Cammittee and checked for accuracy, from the viewpoint of the source and the chemistry involved, before it is listed. We make every effort to examine the basic data to eliminate misinformation and doubtful or conflicting data. Committee members have had long experience in the chemical field, and we insist that the reaction be a t least theoretically possible and that the reactants in the reported incident be properly identified. We cannot hope to list all the possible combinations that theoretically can cause a problem. No. 491M is specifically a listing of reactions that have been reported to he potentially hazardous. Many of them have actually caused fire, explosions, deaths, and injuries in laboratories and plants. The Manual had its beginnings in an extensive survey of the literature conducted by the late George W. Jones of the Bureau of Mines, who for many years served as a member of the NFPA Committee on Chemicals and Explosives. After Mr. Jones's untimely death the Sectional Com-
* This article reprints a paper presented hy Mr. Schwab a t the 1971 NFPA Fall Canference an Fire and printed in the Fire Juurnal fifi(21,89 (Mar. 1972), and excerpts from the "Manual of Hazardous Chemical Reactions," 4th Edition. Both publications are copyrighted by the National Fire Protection Association. Reprinted by permission. t Mr.',Schwah currently serves as editor of the Manual of Hazardous Chemical Reactions" and as Chairman of the Seetional Committee on Hazardous Chemical Reactions, of the Committee on Chemicals and Explosivss, of the National Fire Protection Association.
mittee on Hazardous Chemical Reactions reviewed his compilation and arranged the format published in 1964 as the First Edition of,No. 491M. The 1966 Edition incorporated the remainder of Mr. Jones's compilation, corrections, many contributions from readers of the First Edition, and additions from the recent literature. The 1968 Edition added another 300 reactions, and the 1971 (Fourth) Edition added yet another 350 reactions. The Fourth Edition contains some 2,350 documented reactions. We are still going strong; since publication, my folders have collected another, 30 t o 50 candidates for Committee review, many of which I expect to see listed in the next Edition. We expect to publish the Fifth Edition when 150 to 200 new reactions have been accumulated. You may well ask what all this means. The compilation in No. 491M is the only attempt in the technical literature to list potentially hazardous reactions. A chemist ~roceedine an a research
he hard put to survey the literature; indeed, a large percentage of the material that is listed is not usually contained in the ~ r i n c i ~ chemical al literature reference. ~ h e h ' ~d b s t r a e t s .obtaining the infor: mation from certain specialized hooks can also he quite difficult. The abstracts presented in No. 491M range from reactions that produce incandescence or flame a t moderate or slightly elevated temperatures to those that produce deflagrations or detonations. The Committee recognizes certain inadequacies and possible inaccuracies in the Manual hut hopes that the shortcomings will not impair its over-all usefulness. Since some of the information was obtained from very old references, its validity may he questioned. Many of the reported hazardous reactions may have been the result of impurities or contaminants. On the other hand, absence of a reaction from this list in no way implies that combinations of materials may he mixed with impunity, with or without heating. Similarly, the comments appended to particular reactions regarding their violence should be tempered by consideration of the quantities involved, the temperatures, confinement, and many other factors. There are many references in standard handbooks, the chemical literature, and
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patents that describe very hazardous procedures and combinations of etemicals. Sometimes there is no indication of any hazard. Let me cite two examples, remarkably similar, that illustrate the paint. For many years a well-known and much-used laboratory reference contained a recipe for silvering glass known as Brashear's Process. It involved preparation of a silver nitrate solution with some drops of dilute aqua ammonia. The last paragraph of the written procedure made mention that the action of ammonia on silver oxide is likely t o produce fulminating silver, especially in a warm room, and that all solutions should be thrown away as soon as the silvering operation is completed. Unfortunately the technician who was doing this work was interrupted and was not able to give his undivided attention to the task. When he returned t o it again and commenced stirring, the mixture blew up in his face. That young man is now blind, and the prognasis far his recovery is not promising. Had he reviewed No. 491M he might have been forewarned of the prohlem; but he was not aware of any immediate danger. The other incident involved research work in which details of a patent preparation were described. It was recommended that a silver solution be prepared by dissolving silver nitrate in distilled water and adding an aqueous solution of ammonia, dissolving the precipitate, and adding caustic pellets. Here the chemists were aware of the hazard and had taken pre-
Editor's Note The "Manual of Hazardous Chemical Reactions," NFPA No. 491M1971, (308 pages) is available for $3.25 from the Publications Service Denartment. National Fire Protectioh ~ s s a c i k i o n , 60 Batterymareh St., Boston, Mass. 02110. Reports of hazardous chemical reactions are solicited by the NFPA Sectional Committee on Hazardous Chemical Reactions for inclusion in the Fifth Edition of the Manual, scheduled for puhlication early in 1974. The Committee will begin their work within the neat few months. Reports of laboratory fires, accidents or unexpected chemical reactions should be reported immediately, if they may have value beyond the laboratory of occurrence, by the most rapid means that reaches others who need to know. (Continued on page AISO) Volume 50, Number3, March 1973 / A149
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cautions against personal injury. Nevertheless the explosion was extremely violent, blowing glassware out of the hood and spraying the lab with a brown slurry that on drying continued to "pop." The "pops" were sometimes spontaneous hut could also be set off by tapping the dried slurry with one's finger or a spatula. Although expecting problems, the chemists were surprised by the violence of the reaction. Outside of same ringing in the ears and slight cuts from flying glass, serious personal injury had been avoided. I should comment that the patent describing this process contained even less warning than the recipe in the previous incident. The remarkable similarity of these two incidents, coming only a few months apart, one of them involving a very necessary piece of investigative work, illustrates that there are many published preparation procedures containing little if any warnine. -. and that the unwarv can be led astray. Ammonium hydroxide, silver nitrate, and caustic are a combination with a long sorry history, and most experienced chemists are well aware of the hazards. The ingredients for this combination are also items easily obtained by the neophyte chemist-which compounds the problem. Most of the other combinations contained in No. 491M are not that well known, and a chemist might well receive his first indication of imminent difficulties by consulting theManua1.
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In No. 491M many potentially hazardous reaction mixtures have been brought together into groups. For example, the reactions of mixtures of inorganic perchlo rates with many fuels can be quite violent. Yet the association of different reactants in the same group should not be taken as an indication that all such related compounds react a t equal rates or with equal ease with a given fuel, that there will be equal violence in all cases, 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 profoundly affect the eaune and rate of the reaction. However, an experienced chemist can take precautions if the groupings tend t o show a socalled "class hazard." 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 sub. stances. Finally, any mixture of oxidizing and reducing agents should be suspected of being capable of undergoing a hazardous reaction. The Committee has discussed the possibility of checking some of the reported results in the laboratory. Unfortunately that would take a considerable amount of time and money and specialized laboratory facilities and personnel, all of which are a t present unavailable. If someone wishes to provide the necessary financial support to da such work, I dare say there are others besides the Committee members who would be delighted.
Excerpts from "Manual of Hazardous Chemical Reactions"
ORGANIZATION OF THIS MANUAL In this alphabetic tabulation, the reactions are presented in the following format: PRIMARY ENTRY
Secondary Entries-Remarks ture references.
and litera-
Thus,the entry ALUMINUM
Sodium Carbanate-When sodium carbonate was applied to redhot aluminum, an explosion occurred. Price and Baker, Chem. &Met.Eng. 29: 878 (1923). means that aluminum and sodium carbonate react under the conditions stated nnd that the reierence can he cvnsulted frr pwiihlc additional informarwn. At the end of the mnnunl. the full titles of the ab. breviated names of references are listed. This same reaction will also appear slphabetically under "sodium carbonate" as a cross-entry in bold-faced capital letters on the left margin as follows: ~
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SODIUM CARBONATE
A l u r n i n u m S e e ALUMINUM plus Sodium Carbonate.
The reactant under which the specific remarks are made (the Primary Entry) is chosen u n d e r an arbitrary system of priorities. Generally, the primary entry was selected from the higher an the following list: CHEMICAL Metallic Elements Other Elements Classes of Compounds Uncommon Compounds Specific Compounds of a Class Common Acids Common Bases Common Organic Compounds Nonchemical Names
EXAMPLE Magnesium Bromine Nitrates Cesium Acetylene Carbide Ammonium Nitrate Nitric Acid Sodium Hydroxide Ethyl Alcohol Organic Matter
Additional guides for finding reactions in the manual are listed below: 1. When two chemical compounds are of equal importance, the first in alphabetic listing has usually received priority as the primary entry. 2. Most of the secondary entries appear also as primary cross-entries; exceptions are air, water, common chemical names like alcohol and ether, and trivial or commonnames like caustic soda or wood. Far these common substances, refer to the other reactant or to the specific chemical name. Since so many reactions concern charcoal, this material is a primary entry. 3. For some common organic chemicals, popular names were used in preference to scientific nomenclature; for example, methyl bromide, rather than monobromomethane. 4. A chemical name is used in preference to its creator's name, thus, permanosulfuric acid, rather than Cam's acid. 5. A few proprietary names appear in preference to the relatively unknown chemical identification of the compound, e.g., Teflona instead of polytetrafluoroethylene. 6. If no hazardous reaction is listed for a particular pair of chemicals, the reader should look up possible reactions between chemicals with similar properties. For example, if no reaction is given between cesium and hydrochloric acid, see sodium and hydrochloric acid. The violence of the reaction between the similar chemicals may not he the same, but the combination should be regarded as suspect. 7. The manual does not list explosive fuel-air mixtures, hut does list pyrophoric or hypergolic (self-igniting) mixtures. 8. The manual also lists a number of individual chemicals that explode or detanate spontaneously or in response to impact or heat. In such cases the chemical is listed as the primary entry, under which is printed the term, "self-reactive." 9. A number of entries by "families" of chemicals, e.g., nitrates, sulfates, aldehydes, ethers, are included to facilitate the search for reactions. Frequently, these entries cross-refer to reactions of individual chemicals of the family. 10. Isomeric designations such as "iso" and "n" do not affect the alphabetic arrangement of chemical names in this Manual.
REFERENCES An effort has been made to furnish references complete enough t o lead the reader t o the source of information. At the end of the Manual, the full titles are listed for the abbreviated names of references that accompany the reactions. If a statement about a reaction might disclose proprietary information, the source is protected by the reference, "Confidential information furnished to NFPA."
INFORMATION ON ERRORS AND OMISSIONS WELCOMED The Sectional Committee on Hazardous Chemical Reactions will welcome comments on and criticisms of the present compilation. If a reader can cite more upto-date references or experiences caneerning any of the listed reactions, the information also will be welcomed. Similarly, the Committee would appreciate very much receiving brief details of incidents involving hazardous chemical reactions not yet included in the manual, so that these can be compiled and included in a later revision. Such material should be transmitted to Chester I. Babcock, Secretary, Committee an Chemicals and Enplosives, National Fire Protection Assoeiation, 60 Batterymarch Street, Boston, Massachusetts 02110. Tear-out pages for forwarding new material are a t the back of the manual. ACETALDEHYDE CH3CHO
Acid Anhydrides-Condensation reaetion of acetaldehyde with acid anhydrides, alcohols, ketones, and phenols can he violent. Chem. Safety Data Sheet SD-43 (1952). Air-Acetaldehyde oxidizes readily in air t o unstable peroxides that may explode spontaneously. Chem. Safety Data Sheet SD-43 (1952). Alcohols-See ACETALDEHYDE plus Acid Anhydrides. Chem. Safety Data Sheet SD-43 (1952). Ammonia (Anhydrous)-Reaction of anhydrous ammonia, hydrogen cyanide or hydrogen sulfide can be violent. Chem. Safety Data Sheet SD-43 (1952). Bromine-See BROMINE plus Aeetaldehyde. Chlorine-See CHLORINE plus Acetaldehyde. Fluorine-See BROMine plus Aeetaldehyde. Hydrogen Cyanide-See ACETALDEHYDE plus Ammonia (Anhydrausl. Hydrogen Sulfide-See ACETALDEHYDE plus Ammonia (Anhydrous). Iodine-See BROMINE plus Acetaldehyde. Ketones-See ACETALDEHYDE plus Acid Anhydrides. Phenols-See ACETALDEHYDE plus Acid Anhydrides. Sodium Hvdraxide-A violent oolvmer, ipation of acetaldehyde resdlta from rmrtioni with alknline marer~alssuch u i iodium hydroxide. Dqvle (1966).
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(Continued on page A152) Volume 54 Number 3, March 1973 / A151
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BARIUM
ManOfluoratrichloromethane-See BARN M plus Trichlorotrifluaroethane. Tetrachloroethylene-See BARIUM plus
Trichlorotrifluoromethane. Trichloroeth~lene-See plus Trichlorotrifluoraethane. Trichlorotrifluoroethane-It has been determined experimentally that mixtures of finely divided barium metal and a number of halogenated hydrocarbons possess an explosive capability. Specifically, impact sensitivity tests have shown that granular barium in contact with monoflutrichlorotrifluaorotrichloromethane, roethane, carbon tetrachloride, trichloroethylene, or tetrachloroethylene can detonate. ASESB Pot. Incid. 39 (1968). Aero. and Astro. 6 (3):82 (1968). Chem. Eng. News 46 (9):38 (1968). NITROGEN TRICHLORIDE NCls
ex. ~ trichloride ~ ~ with am. nitric mania, arsenic, hydrogen oxide, organic matter, ozone, ,,hosphine, phosphorus, potassium cyanide. potassium hydroxide, or selenium. H. Davy, Phil. Trans. Roy. Soc. London 103: 242 (1813). Comp. Rend. 70: 539. E. Schneider, Report Anal. Ckem. 1 : 54 (1881). ~
,
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POTASSIUM SUPEROXIDE KO2
Ethyl Alcohol-To
dispose of a piece of
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sodium potassium waste, it was placed in a glove box, which was then purged with argon for 10 minutes. When 10 ml of alcahol was added to the waste, an immediate pressure rise caused the glove to burst and flame issued from the part. Also, a highly oxidized sphere of ~ o t a s s i u mwas cut in two and one half was dropped into a dish of alcohol; an immediate explosion shattered the dish. Potassium superoxide was considered the cause of both incidents. ~ e a l t kand Safety i n f 251 (March 31,
sodium peroxide, 0.2 g dextrose, and 0.2 g potassium nitrate; actual proportions were 0.35 g, 2.59 g, and 0.2 g respectively. There was insufficient sodium peroxide to dissolve decomposition gases, hence a rapid temperature and pressure build-up caused the P a n bomb to burst. Tennessee Eastman (1967).
~ acm &"".,.
Aervlonitrile-The reaction of 1.2.3.4, . . tetrat&drocarbazole with aerylonitrile, initiated by benzyl-trimethyl-ammonium hydroxide, is described in J. Am. Chem. Soc. 72: 4313 (1960). For a run eight times the literature scale the initiator was added at o0c, the ice hath removed, the reaction flask placed an the steam bath and the steam turned an. After 30.60 seconds an explosion shattered the apparatus. BCISC 39 (156): 36 (1968). wisekmqer (1970). NSC Newsletter, R &D see. (Feh. 1970).
SODIUM
Carbon Dioxide-Molten sodium can be plunged into a carbon dioxide atmosphere without causing a vigorous reaction. But sodium manufacturers warn against using carbon dioxide on fires, because molten sodium burns with increasing vigor as the temperature is elevated. Small sodium fires can, however, he covered with solvent. like kerosine. and the resultant kerasine with~carbon dioxi fire can~ be attacked i ide. H. N. Gilbert, Chem En#. News 26: 2604 (1948) Metallic Sodium. p. 19 (1952). " E t k y y Sodium. P. 10 (1954). Sodium. P. 38
Dextrose and Potassium Nitrate-A micro Parr calorimeter exploded when the wrong proportions of these ingredients were used. The intended mixture was 4.0 g
~,~,~,~.ETRAH~DROCARBAZOLE C,~H,~NH
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POLYACETYLENE EXPLOSION
A 7-gram sample of 2,4-hexadiyn-1.6hischloroformate, prepared from phosgene and2,4-hexadiyn-1, 6-did,
0
11
CI-C-OCH,C=C-CEC-CH1-0C-C1
0
11
detonated with extreme violence a t room temperature while under a vacuum of 0.15 mm. Hg. The tendency t o eliminate two moles of HC1 and two moles of COz seems a likely cause for the explosive nature of this compound. The explosion sheared several metal clamps and shattered an acrylic safety shield. A previous 3.5-gram sample, however, was distilled a t 0.15 mm. Hg and 114" to 115' C. Without incident. This occurrence prompts us to report that impact testing done on the related 2,4-hexadiyn-1.6-dichloride revealed that this
compound is extremely shock sensitive, so that an impact of 4 kilogram centimeters is sufficient to cause detonation in 50% of the drop test runs. For comparison, the 50% level for propargyl bromide is 3.5 kilogram centimeters and for nitroglycerine, 2.0 kilogram centimeters. The very hazardous dichloro-compound has been prepared in quantity (500 grams) by Armitage and Whiting (J. Chem. Soe., 2005 (1952)) and has been used very recently by Besace, Marszak-Fleury, and Marszak (Bull. Soe. Chim. Fr., 1468 (1971)) to prepare the corresponding diiodohexadiyne
which we regard as being an equally hazardous material. We note further that preparation of the diehloro compound from 2.4-hexadiyn-1,6-dio1 and thionyl chloride probably includes intermediate formation of the corresponding bischlarasulfite
which is closely analogous to the hischloroformate that exploded. Low temperatures were required to prevent a hexadiyndiolSOCIS-dmf reaction from decomposing vigorously to give carboniferous material and excessive heat. Research on these compounds was discontinued, and we urge that great caution be used in preparing ar using any of the above compounds. (Report 130) -KODAK RESEARCH LABORATORIES ROCHESTER, N Y . Reprinted with permission from Research and Development Seetion-Safety Newsletter, June, 1972. Published by National Society Council, Chicago 111.60611
IRRADIATED SAMPLE EXPLODES
An employee sealed approximately a milliliter of aqueous ammonium bromide in a quartz tube. The sample was irradiated in a reactor for 14 hours a t a flux of 3r1013 neutrons/cmz/sec (gamma irradiation was similar). The employee placed the quartz envelope in a lead pig in a glove box. Upon opening the quartz, the gases above the liquid exploded with a flash and
a report. The employee received a minor scratch from a particle of quartz which penetrated the rubber glove. The enormous energy within a reactor produces a very complex assortment of decomposition materials within an irradiated sample. Hydrogen and oxygen are known to form over pure water, and pressure build-up in irradiated samples is common. A variation of "Murphy's law" appliesany combination of gases which could he formed in the high energy areas of a reactor will he formed (though usually in very small quantities). Two procedures which minimize gas surges are: (1) leave an adequate volume far expansion above the sample and seal in a vacuum if possible, and (2) freeze the sample in liquid nitrogen before attempting t o open it. (Report 97) Reprinted with permission from Research and Develooment Seetion-Safetv Scw+tter, June, i972 Puhhshed by SZ'. rinnnl Snfrry Council. C ~ I I J CIll. O 60611
EXTINGUISHER EXPLOSION
In 1962 a fire extinguisher exploded. The extinguisher was of the 15-pound, COz portable type. The ambient temperature was taken 15 minutes after the explosion and was 102 degrees Fahrenheit. The extinguisher was apparently manufactured about 1948, as the following information was stenciled on the body of the eutinguisher: 9-53 and 11-58 indicating that the extinguisher was hydrostatically tested in 1953 and 1958.
It is believed the extinguisher exploded, not from excessive pressure, but from weakening of the vessel body by a loss of metal, under a three-inch stainless steel band around the body of the extinguisher. Metal loss was caused by electrolytic action between two dissimilar metals. It is important to note that no indication of the metal loss can be seen until the steel band is removed. Operating and maintenance instructions are stenciled on the steel band. All of the COz-type fire extinguishers within the plant have been inspected. Any extinguishers of doubtful appearance have been removed, discharged, and a new extinguisher put in its place. The extinguishers of doubtful condition have been discarded or will be sent out for hydrostatic test. The steel bands will be removed from all of the COz-type extinguishers. The extinguisher nozzles will be held by clamps attached to the wall or beam on which the extinguisher is hung. (Report 129)
Reprinted with permission from Research and Develooment Section-Saietv K&letter, June, i972. Published by ~ a tional Safety Council, Chicago Ill. 60611 ~
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