We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
288 FIVE RECENT AMERICAN STANDARDS March
Definition of Safety Film
The American Standard Definition of Safety Photographic Film Z38. 3. 1-1943 defines a photographic film which is no more hazardous than common newsprint paper. In order to be classified as Safety Photographic Film, a photographic film must (a) be difficult to ignite, (b) be slow burning, and (c) evolve a limited amount of toxic oxides of nitrogen during decomposition.
The ease of ignition is determined by measuring the time of ignition after subjecting the sample to a uniformly maintained high temperature. The requirement for ease of ignition and the test method are the same as those specified by the British Standard Definition of Cinematograph "Safety" Film (1939) and other European standards for safety motion picture film.
The rapidity of burning and the method of measuring that characteristic are also the same as specified in the British Standard Definition of "Safety" Film (1939).
The toxic gases evolved when photographic films of cellulose nitrate are decomposed by heat are oxides of nitrogen, carbon monoxide, and hydrocyanic acid. Laboratory tests made available to the committee indicate that only oxides of nitrogen and carbon monoxide are evolved in sufficient quantities to constitute an appreciable hazard. These tests also indicate that photographic film does not evolve more carbon monoxide than does common newsprint paper when equal quantities of film and paper are decomposed in the same manner.
The maximum quantity of oxides of nitrogen which can evolve when safety photographic film decomposes is limited by stipulating in the definition the maximum nitrogen (present as nitrate) content of the material. Fumes from photographic film that comply with this standard will not be significantly different from fumes evolved from ordinary newsprint paper decomposed under the same conditions.
Photographic films made from materials for which this definition applies but which do not comply in one or more respects are not necessarily hazardous. For example, acetate film may fail to comply with the maximum nitrogen content specified in this definition and still not be significantly more hazardous than common newsprint paper under ordinary conditions.
The committee considered a maximum nitrogen content of 0.72 per cent and had some evidence that a safety film containing that proportion of nitrogen was no more toxic than films with a lower content.