May, 1933
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INDUSTRIAL AND ENGINEERING CHEMISTRY
SUMMARY
breath till he can get out, to use it only on beginning fires which can be extinguished so quickly (0.5 to 1 minute) t h a t he need not breathe while doing it, and not to use carbon tetrachloride on fires in narrow spaces where escape cannot be made quickly. Negative evidence as to the occurrence of occupational poisoning is of little value in this country, but i t certainly is significant t h a t no cases of phosgene poisoning from this source have been reported by German factory inspectors. (One fatality attributed to phosgene was caused by the thermal decomposition of trichloroethylene, 1923-24.) Flury and Zernik say that in addition to the Portsmouth accident there have been some accidents involving German firemen, but they give no detail^.^ . On the other hand, the French have lately been emphasizing the danger of carbon tetrachloride as an industrial poison and of phosgene gas formation from its decomposition when used as a fire extinguisher. T h e Paris correspondent of the Journal of the American Medical Association (3) states that the latter use of carbon tetrachloride has given rise to the most serious accidents, “several examples of which have been reported recently in various parts of France.” T h e only case histories given are those of two men (reported by Mollaret of Grenoble) who used a rather large quantity of carbon tetrachloride extinguisher on a fire caused by a short circuit in a poorly ventilated room. The description of their symptoms, nausea, gastric disturbances, jaundice, prostration, is suggestive of carbon tetrachloride rather than of phosgene. At a recent meeting of the Medical Society of Paris (4) the subject was discussed, various cases reported, and the organization resolved to demand the inclusion of carbon tetrachloride among the dangerous poisons.
Foreign experiments have borne out the findings of the Bureau of Mines with regard to the formation of phosgene and other toxic gases in the decomposition of carbon tetrachloride byheat, and, while the number of cases of actual injury reported from this source seems t o be very small, the conclusion to be drawn from the literature is that fire extinguishers of the carbon tetrachloride type should not be used in inclosures where the ventilation is not sufficient to dilute the products of thermal decomposition below the danger point, especially if quick escape from the place is not assured.
LITERATURE CITED (1) Anonymous, Jahresbericht chem-tech. Reichsanstalt, (1926). (2) Ibid., 6,57-63 (1927). (3) Anonymous, J . Am. Med. Assoc., 98, 2299 (1932). (4) Ibid., 99, 1276 (1932). (5) Biesalski, E., 2. angew. Chem., 37, 314-17 (1924).
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11-20
(6) Fieldner and Kats, Bur. Mines, Rcpt. Investigations 2262 (1921). (7) Fieldner, Katz, Kinney, and Longfellow, J . Franklin Inst.,
190, 543 (1920). (8) Flury, F., and Zernik, F., “Schiidliche Gase, DRmpfe, Nebel, Rauch- und Staubarten,” pp. 222, 502, Springer, 1931. (9) Fohlen, J., Tech. moderne, 14, 593-6 (1922). (10) Hamilton, Alice, “Industrial Poisons in the U. S.,”hlacmillan, 1925. (11) Henderson, Yandell, and Haggard, H. TV., “Noxious Gases,” Chemical Catalog, 1927. (12) Katz, Gleim, and Bloomfield, Bur. Mines, Rept. Investigations 2499 (1923). (13) Lehmann, K. B., Zentr. Gewerbehyg. Unfallverhiit., 17, 123-33 (1930). (14) Kuckolls, H. H., Quart. Xatl. Fire Protect. Assoc., 14 (3), 221-36 (1921). (15) Olsen, J. G., Ferguson, G . E., Sabetta, V. J., and Soheflan, L., IXD. EXG.CHEY.,Anal. Ed., 3, 189-91 (1931).
4 Neitzel [Geaundh. Ing., 51, 561 (1928)l writes of an accident to six firemen in Westphalia, who mere overcome by the fumes of carbon tetrachloride extinguishers, lost consciou~ness,and later complained of irritation of the upper air paasages and of inflamed eyes: however, Neitzel thinks that phosgene was not the causative agent, but rather vapors of carbon tetrachloride with hydrochloric acid and chlorine.
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541
(16) Stahl, R., Zentr. Gewerbehyg. Unfallsverhiit., [N.S.1, 5, 78-80 (1928).
(17) Wirth, F., Chem.-Ztg., 49, 615-17 (1925). RECEIVED January 19, 1933. e
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Discussion of “Formation of Phosgene in Thermal Decomposition of Carbon Tetrachloride” J. C. OLSEN,~The Polytechnic Institute of Brooklyn, Brooklyn, N. Y.
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T MAY not be clear to the reader of A. Hamilton’s article in what respect her book “Industrial Poisons in the United States” was termed “misleading and inaccurate’’ in the complaint which she cites, or t o what she has reference when she explains t h a t “the information given (in the book) covered all that was available in 1924.” T h e following paragraph from t h e letter making the complaint to which she refers may serve to make this point clear: On page 444,Dr. Hamilton alleges that “according to an industrial insurance man, six deaths are known to have occurred recently from the use of this form of fire extinguisher.*** We have tried t o ascertain the source of Dr. Hamilton’s information but she has failed to give these data. In this connection it is interesting to note that one of our number alone, who has the summation readily available, has itself sold some 5,770,000 charged extinguishers and some 7,500,000 refills of liquid therefor over the period from 1910 t o 1930. No one of our companies has ever received any evidence whatsoever of a single fatality due t o the use of an extinguisher of the carbon tetrachloride type. Hamilton has stated in her article: “I have never been able to verify the statement, quoted in m y book (IO) of a n 1 Technical representative of the Vaporizing Liquid Division, Chemical Fire Extinguisher Association.
industrial insurance man t o the effect that six deaths had occurred from the use of this form of fire extinguisher.” This statement has the effect of removing from the literature this error which is of a type that occurs too often. Another pertinent paragraph from the letter making the complaint, t o which Hamilton refers, is as follows: In speaking of t? Portsmouth incident also on page 443, Dr. Hamilton states: *** the other threw Pyrene (sic) fire extinguisher over the clothing to put it out. Both men were overcome by the fumes so that they could not save themselves ***.” The innuendo and inference that the fumes which overcame these men were those of Pyrene we most definitely deny. It is well known that peo le are often overcome by smoke and fumes from fires, and deatxs from this cause are not infrequent. Hamilton has clarified and amplified this statement by saying that she first explained the death of the two men concerned as caused by inhalation of carbon tetrachloride vapor, whereas later she became convinced that death was caused b y phosgene poisoning. As the physiological action of these compounds is quite different, it is obvious that no scientific medical basis existed for either of these diagnoses. Hamilton gives no evidence that phosgene is produced by spraying
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I N D U S T R I A L A K D E N G I N E E R I N G C H E h4 I S T R Y
carbon tetrachloride fire-extinguishing liquid upon burning clothing. As other poisonous gases are produced by the burning of clothing, still other causes of death might more reasonably have been assigned. The physicians a t the hospital reported pneumonia as the cause of death. As is well known, exposure to cold, severe burns, or infection b y the mouth and other causes may produce this disease. These men were severely burned and subjected to subzero weather. Hamilton cites an eminent German scientist-namely, K. B. Lehmannand states t h a t he does not agree with her conclusion as to t h e Portsmouth case. The number of extinguishers of carbon tetrachloride type in use in the United States, Europe, and other countries is conservatively estimated t o exceed ten million. This type of extinguisher has been in use for twenty-five years by all kinds of people in all sorts of rooms and inclosures. \Ye are indebted to Hamilton for a thorough search of the literature, and she has found but the one case (Portsmouth) where conditions were such that she believes death to have been caused by phosgene poisoning resulting from the use of this type of extinguisher. She has been able to find few cases of even minor injuries resulting from the use of the carbon tetrachloride type of fire extinguisher. Inasmuch as the gases produced by fires when extinguishers are not used are highly toxic and a great many people are overcome or lose their lives from exposure to smoke alone, i t may be seriously doubted if the extinguisher gases have ever caused any measurable or appreciable increase in the toxicity of the atmosphere surrounding the fire. Furthermore, it is obvious t h a t extinguishment of the fire will, in every case, stop the formation of toxic fire gases. It is possible t h a t Hamilton has given too much weight t o the results of laboratory experiments, and the danger which she believes exists may be wholly academic and theoretical. Hamilton has given a summary (page 541) of the extensive literature on the decomposition of carbon tetrachloride and the possible danger from the use of the carbon tetrachloride type of fire extinguisher arising from the fact that under some conditions phosgene is formed in small amounts when this liquid is used upon certain types of fires. If a chemist were familiar with the reactions taking place when a fire is extinguished by means of carbon tetrachloride fire-extinguishing liquids and if he could estimate the ventilation necessary to “dilute the products of thermal decomposition below the danger point” and the poisonous products of combustion of the fire, he might be able t o follow such advice as Hamilton gives, The warning would most certainly be useless for laymen and most chemists or other technical men. The probable effect would be to prevent the use of a n extinguisher of this type which, t o be effective, must be used promptly. Inasmuch as an extinguisher so convenient to use and so efficient for extinguishing incipient fires has been the means of saving property valued a t millions of dollars and innumerable lives, i t is inevitable that a warning against its use, if i t were heeded, would be the cause of great property loss and many fatalities. It is certain t h a t the millions of extinguishers which are in service have been limited in their use only by the common sense and judgment of the operator, and the practical record shows no need for any warning.
S O A P PREPARATIONS ON THE LITHUANIAN hfARKET. Soap is the most widely advertised commodity on the Lithuanian market, where German methods in the manufacture and distribution are generally used. Production of toilet soaps, according to the combined estimates of the Ministry of Finance and an im ortant local syndicate, amounted in 1932 to 250 metric tons vaged at 11CO,OCO, a drop of one-fifth in value from the previous year. Domestic brands have gained sufficient acceptance to
Vol. 25, No. 5
Hamilton quotes a warning given by the Bureau of Mines as the result of having obtained very high concentration of phosgene in experimental work involving fires: “Such extinguishers should not be used b y persons unprotected from the fumes, who are unable to hold their breath long enough to escape from the dangerous atmosphere.” She then states: “Similar conclusions were reached by Nuckolls (16) in an investigation made for the Underwriters’ Laboratories.” The conclusion of the article published by Kuckolls in 1920 is as follows: In thousands of tests in extinguishing fires with carbon tetrachloride extinguisher liquids no apparent injury to the health of members of the staff of Underwriters’ Laboratories has been experienced, although the irritating fumes caused lachrymation and in some cases resulted in a subnormal feeling lasting for several days. These tests were run under varying conditions covering a period of twelve years, and included the use of small rooms partly ventilated, with repeated exposure in some cases for hours at a time. One certainly would not be led to believe from this that such serious danger exists as was indicated in the quotation from the report of the Bureau of Mines. As a matter of fact, the Bureau of Mines makes the following statement: It is not the intention of this paper to discourage the use of carbon tetrachloride fire extinguishers which are very effective for stopping incipient fires because, in most cases, ventilation or the large amount of air usually present prevents the formation of dangerous concentrations of gas. Also the operator can nearly always escape easily and quickly from the vicinity of the gas when he knows he should do so. Rather, the purpose is to show the danger of using such extinguishers in small, unventilated places where escape is impossible.
Lehmann (reference I S of Hamilton’s article) makes t h e following statement: To the best of my knowledge there is not a t present a single case known of pure phosgene poisoning which followed the use of carbon tetrachloride-i. e., a case in which a person left the place of a fire scarcely injured and irritated only slightly in his breathing organs, and who after a few hours became seriously ill with edema of the lungs. Ordinarily by “injuries from phosgene” are meant those usually slight irritational effects which are caused by slight inhalations of hydrochloric acid and which disappear after several hours, or at most a few days. Similar symptoms are produced by smoke alone. The literature mentions only a few cases of ‘
