Nitrate film: reformatting and treatment considerations
The first step in treating nitrate film is to correctly identify that the film is indeed nitrate. Fischer (n.d.), of The Northeast Document Conservation Center (NEDCC) lists ways to identify nitrate film:
1) The date of the film from the 1890s - 1950, though some later films may still be on nitrate;
2) The characteristics of film deterioration (see below), which are unique to nitrate;
3) By conducting one of several tests as described by Fischer of the NEDCC (n.d.).
The film should be examined for damage. In its earliest stages of decomposition, a film may still be preserved and duplicated.
Evidence of early stages of decomposition include:
- Amber discoloration and image fading;
- Film sticks together or becomes brittle;
- A noxious smell caused by gas bubbles on the film (National Media Museum, n.d.).
In its advanced stages of decomposition, the film is beyond recovery and you should contact environmental health officials or the fire department about safe disposal. Evidence of advanced stages of decomposition include:
- Film becomes soft, becomes "welded to adjacent film" and may be covered with "viscous froth";
- Film deteriorates into a "brownish acrid powder" (National Media Museum, n.d.);
Deterioration can be slowed by providing the film proper storage in a cool (no higher than 70 degrees F), preferably below freezing (Edmunds, Fairall, Lucas, & Martin, 2012), temperature controlled, and well-ventilated facility with a relative humidity of between 20 and 45 percent. (Kodak, n.d. and U. S. Department of Interior, National Park Service, 2003, June). Any dirt on the surface of the film may be carefully removed with a "quality cleaner," according to Kodak (n.d.).
Nitrate base films may be reprinted onto safety base film if the decay is not too far advanced. However, even after copies are made, Kodak (n.d.) recommends preserving the originals because “first-generation elements in good condition usually provide better image quality than any copy” (Kodak, n.d.). However, if the film is excessively deteriorated and must be discarded, it will need to be treated as hazardous waste (National Film Preservation Foundation, 2004).
Before making a treatment or disposal decision, it is advisable to contact a specialist in film preservation. Because of the volatile nature of the film, it cannot be readily shipped (National Film Preservation Foundation, 2004).
George Eastman House, 2013. https://www.youtube.com/watch?v=IwfxH2r7SS0