International projectionist (Jan-Dec 1949)

Relative Toxicity of Nitrate and Acetate Film Stock By DR. E. K. CARVER Research Laboratories, Eastman Kodak Company RECENTLY IP posed the following question: "If acetate film should ignite, would it give off the same toxic fumes as nitrate?" The answer to this question is "no". Acetate film is about like paper or wood in this respect, but is considerably harder to burn than either of them. No one likes to breathe acetate wood smoke, nor would they like to breathe acetate film smoke. One is about as bad as the other. The toxic fumes from nitrate film are chiefly nitric oxides, although carbon monoxide is also generated. It is the nitric fumes which are insidious. Breathing them may bring on edema of the lungs many hours after exposure. The victim may not know of this danger and so may not seek proper medication until too late. Acetate film cannot give off these nitric oxides. Vital Difference in Characteristics However, the chief danger from nitrate film is really caused by the large volume of fumes that can be given off rapidly even in the absence of sufficient air to support combustion. If nitrate film were no more combustible nor more liable to decomposition than acetate film, there would be little toxicity hazard except All Kodak Projector Prices Slashed Kodak's two popular 16-mm sound projectors— the Kodascope FS-10-N and the FB40 projectors — have been reduced in price. The FS-10-N single-speaker unit has been dropped from $500 to $345. The twinspeaker unit formerly priced at $565 is now $395. The FB-40 projector, which has the greatest undistorted watt output now available from a portable tungsten 16-mm sound-projection equipment, 40 watts, has been reduced from $855 to $585. Both of these projectors are equipped with Kodak's unique fidelity tone control which assures the finest sound reproduction from all types of 16-mm. sound films — originals, duplicates, or reduction prints from 35-mm. And, like all Kodascope projectors, these two units are equipped with the exclusive field flattening element of their lenses which results in corner-to-corner sharpness on the screen. under very special circumstances. It is the fact that nitrate carries its own supply of oxygen that really makes it hazardous. Acetate film burns very slowly and does not decompose at all unless there is an outside source of heat. It is a bit difficult to understand why this point has come up. It would be possible, if some one were attempting to prove that acetate film were dangerous, for them to quote figures showing that if acetate film were roasted by some source of outside heat, it could be made to give off toxic fumes. This is also true of wood, paper, wool, rayon and many other materials which we do not ordinarily consider hazardous. BOOK REVIEW An Introduction to Color, by Ralph M. Evans. 340 pages, 7% x 10, profusely illustrated, including 15 color plates, indexed. $6. John Wiley & Sons, New York; Chapman & Hall, London, or at all Kodak stores. A completely descriptive and non-mathematical book on color, intended for all persons interested in the subject — including photographers, designers, interior decorators, artists, engravers, and many others — has re You Sell A Picture On a Screen... Make It the Best with f^nJe£ You invest heavily in a building, equipment, and personnel to sell one thing ... a moving picture on a screen. You can't afford to skimp on that. Your screen images must be the finest . . . critically defined, uniformly brilliant, pleasant to look at. One way you can be sure that your screen images are the finest is to use Bausch & Lorab Super Cinephor projection lenses, the standard of excellence in the theatre field. Bausch&Lomb Optical Co ., 616-C St. Paul St., Rochester 2, N.Y. BAUSCH & LOMB OPTICAL COMPANY ROCHESTER 2, N. Y. 24 INTERNATIONAL PROJECTIONIST • March 1949