Showmen's Trade Review (Jan-Mar 1947)

SHOWMEN'S TRADE REVIEW, January 4, 1947 E-l Film Fire Fumes ARE Deadly — Take ISO Chances Erroneous Use of Chemical Term, Widely Circulated, May Lead To Dangerous Underestimation of the Deadly Menace Fumes emitted by burning motion picture film ARE seriously dangerous to life and health. The Underwriters' regulation — requiring projectionists in case of film fire to operate the safety devices and immediately leave the projection room — does NOT represent an exaggerated precaution. Because of an apparently widespread difference of opinion in the industry on these points, STR has checked with the American Medical Association and the National Safety Council, and is in a position to offer accurate facts, from sources of unquestionable authority. A great deal of the confusion and difference of opinion that exists in the matter may possibly have arisen from the circulation of certain erroneous statements, to the effect that burning film produces nitrous oxide, and that this gas causes death or serious lung injury. Many in the industry reading or hearing these statements doubtless recalled that that same chemical (nitrous oxide) is the "gas" the dentist gives when he extracts a tooth, and that surgeons use it as an anesthetic. Consequently it can't be so dangerous to breathe! Others, no doubt, remembered from their high school or college chemistry that nitrous oxide is not particularly a harmful substance. A natural impression has resulted, and won considerable circulation — namely, that the danger of breathing film fire fumes has been enormously exaggerated. That impression is a mistake — one that can cost human lives! If you hold it, it may cost yours. The mistake arises from a simple chemical error in the statements referred to. It is not the almost harmless nitrous oxide that is emitted by burning film, but the very dangerous nitric oxide (which no one would dream of administering as an anesthetic) and its deadly twins, the dioxide and tetroxide of nitrogen. The Chemistry Of It Dr. Morris Fishbein, Editor of the Journal of the American Medical Association, and F. A. Van Atta, Industrial Hygienist of the National Safety Council, have definitely cleared up this point in letters to STR. The latter writes: "Nitrogen dioxide (NO*) and nitrogen tetroxide (N^O.) are evolved, together with other gases. So far as I know, nitrous oxide (N20) is never formed in the decomposition of nitro-cellulose film. ... If formed, it would be quite stable and is comparatively harmless. "Nitric oxide (NO) might be formed and . . . would immediately oxidize with the ozygen of the air to make nitrogen dioxide or nitrogen tetroxide. "Nitrogen dioxide and nitrogen tetroxide do form a mixture of nitrous and nitric acids in the body, and are consequently quite dangerous. The American Standards Association has set the maximum concentration for prolonged exposure at 25 to 5 parts of nitrogen dioxide Precaution A statement erroneously referring to the dangerous gas from burning film as "nitrous oxide" (which it is not) apparently has been widely circulated in the industry and particularly the theatre field. Many in the industry may find it a desirable precaution to take effective steps toward helping correct ny mistaken notions about that. The gases released by burning film — as the accompanying article establishes beyond all question — are not nitrous oxide and they are deadly. Alert projectionists may wish to take up this matter through their union locals, and managers and circuit executives through their normal channels of employe relationship. per million parts of air . . . 200 parts per million may be dangerous on even very short exposures." Mr. Van Atta also adds his expert endorsement to the Underwriters' regulation which requires projectionists to leave the projection room in cases of film fire. (See STR for June 22, 1946, Page E-18). "The regulations of the National Board of Fire Underwriters for nitro-cellulose motion picture films, as given in NBFU Pamphlet No. 40, set forth the following procedure in case of fire: 'In the event of film fire in a projector or elsewhere in a projection or re-wind room, the projectionist should immediately shut down the projection machine and arc lamps, operate the shutter release at the nearest point to him, turn on the auditorium lights, leave the projection room and notify the manager of the theatre or building.' "This is probably as good a piece of advice as you could get, although what to do in any specific set of circumstances must admittedly be a matter of some judgment." Dr. Fishbein of the American Medical Association confirms the above chemical facts, citing an official report: "The principal toxic gases resulting from nitrocellulose film are carbon monoxide and 'nitrous fumes'. By 'nitrous fumes' are meant the poisonous oxides of nitrogen, NO, N02 and N,0*." Dr. Fishbein also forwards a vigorous editorial from the Journal of the American Medical Association of May 25, 1929, which confirms not only the chemical facts stated but the very dangerous nature of the gases that are emitted. It reads in part: "The inflammable type of film is prepared from nitrocellulose, or nitrated cellulose, as it is frequently called; the substance is one quite familiar to those who have studied explosives and the effects of their gaseous by-products. When the product is subjected to combustion — or 'explosion' — there are produced among other substances carbon monoxide and nitric oxide. Nitric oxide . . . quickly takes on oxygen, forming nitrogen dioxide or its polymer nitrogen tetroxide. The Medicine Of It "The nitrogen tetroxide, as well as any unoxidized nitric oxide, readily reacts on the lungs and with the hemoglobin of the blood. Deaths from inhalation of socalled nitrous fumes have been reported many times." In a footnote to this editorial the AM A Journal adds: "The oxides of nitrogen discussed here do not include nitrousoxide (N20), which is well known to the medical profession as an anesthetic." The editor of the Journal of the American Medical Association has some further comment on the subject on another page of the same issue — that of May 25, 1929. He notes: "Poisonous gases likely to arise in connection with the burning of motion picture films are the oxides of nitrogen, if cellulose nitrate films are used, and carbon monoxide. The so-called safety films are believed to be cellulose acetate. In addition there may arise some carbon dioxide and in the case of the acetate films gases of complex nature are derived from the acetate component. Most states and cities require boothing for housing motion picture operations, particularly if the machines are located in the same rooms occupied by public audiences. This is especially true if the films used are of the cellulose nitrate variety. "These booths, while serving the interests of the audience, may increase the exposure for the operator, since the gases created are confined to small spaces." . . . There it is! The gases emitted are not nitrous oxide, not the harmless dental anesthetic. They are fatally poisonous and good things to get away from — fast. (#3).