National Archives and Records Service film-vault fire at Suitland, Md. : hearings before a subcommittee of the Committee on Government Operations, House of Representatives, Ninety-sixth Congress, first session, June 19 and 21, 1979 (1979)

19 Second, part IV of the report indicates that the PBS engineers reported the building's air-conditioning system was operating the day of the fire. Our fire investigators interviewed workers in the building that day and received information that the air-conditioning compressor was cycling repeatedly on and off, and that both supply and return Freon lines were hot to the touch, indicative of low Freon. There had apparently been a leak in the cooling system for about 2 months, which was being treated with regular doses of Freon. The building supervisor had reported the possibility that the system needed Freon 6 days before the fire, and the system was checked the morning of the fire. Our efforts to interview the worker who checked the unit were futile, so we were unable to determine what work, if any, was done. The unit did continue to cycle on and off through the morning. Also, the contractors working in the building reported that the area in which they were working was warm enough that they removed their jackets while working inside and put them back on to go outside to perform duties. We have received information from Mr. Al Daily, the refrigeration man for the Kocharian Co., the contractor working in the building that day, which was later substantiated by Mr. Cross, our independent heating and air-conditioning consultant, of the characteristics of the type air-conditioning unit in service at the Suit land Federal Center. Conditions of low Freon and low ambient temperature, such as existed on the day of the fire, lead to erratic operation of the unit. Wlien this occure, heated Freon gas, in excess of 100°, bypasses the system's condensing unit and is pumped directly into the vault fan units. In effect, the system thus becomes a heating unit, and it is quite reasonable to assume temperatures of over 90° in closed vaults. Storage of cellulose nitrate film is recommended by Eastman Kodak Co. to be in areas of 50° F., or below with a relative humidity of 40 to 50 percent. According to the U.S. Weather Bureau, the relative humidity on the morning of the fire ranged from 66 percent to 79 percent. In the days immediately preceding the fire, it was almost constantly above 50 percent and ranged up to 97 percent. Thus, the film was stored in conditions that exceeded recommendations in both temperature and humidity. Archivists believe the humidity may be more important than temperature as it relates to accelerated decomposition of the film. Above these limits of temperature and humidity, the film begins to decompose. The decomposition process is a chemical reaction that produces its own heat, produces its own oxygen, produces its own flammable vapors, and feeds upon itself, leading to even faster and faster decomposition. If unchecked, this chemical reaction eventually leads to spontaneous ignition of the film. I feel it would be appropriate to briefly examine building A in light of existing fire protection standards and in particular, the National Fire Protection Association Standard No. 40. In the report, several references are made to NFPA pamphlet No. 40. This pamphlet is written by the National Fire Protection Association, and is solely devoted to recommendations and model fire codes regarding the storage and handling of nitrate film.