Storage Vaults

The highest degree of protection for a large number of records is afforded by a fireproof storage vault or record room. It should be located and constructed in accordance with the local building code, Fire Underwriters’ Regulations, and the requirements of the National Fire Protection Association (NFPA)7 for a valuable record room, except that an approved, controlled, air-conditioning unit should be installed. While NFPA discourages air conditioning such an installation, the fire hazard introduced by openings for air-conditioning ducts can be overcome by the use of automatic, fire-control dampers approved by Underwriters’ Laboratories, Inc. These can be installed in the ducts in accordance with recommendations of NFPA.8 Sufficient insulation should be provided in the vault to permit satisfactory temperature control at all seasons of the year and to prevent moisture condensation from forming on the walls.

Cabinets and Safes

For smaller quantities of records, a fire-resistant cabinet or safe of the type described by NFPA7 will provide considerable protection. Such a safe should protect records against a severe fire for at least four hours.

Many fire-resistant safes and cabinets use a type of insulation that when heated releases moisture and thus fills the interior of the safe with steam during a fire. This can cause melting or stripping of the film emulsion layer and loss of the image. For protection, films stored in such a safe should be placed in moisture-tight cans, as described under “Humidity Control” in this publication.

It is preferable to use fire-resistant safes that are available with an inner chamber sealed against moisture. These are classified by Underwriters’ Laboratories, Inc., as Class 150 Record Containers.9 Film damage caused by steam

is not a problem with these safes.

The question is sometimes raised as to whether microfilm stored in drawers or cabinets designed to resist fire for several hours might, in case of a fire, generate enough pressure to damage or explode the cabinet. There is practically no danger of an explosion from the storage of either Estar Base or acetate base safety film under these conditions. There are small amounts of organic materials in acetate film base, as well as

moisture, which will expand under heat and, under some conditions, might generate slight pressure. However, such intense heat would be required on the outside of the fire-resistant cabinet that the cabinet would be seriously damaged from the fire before appreciable pressure developed.

Effects of High Temperatures

In addition to complete loss by fire, damage to film records can also occur if they are exposed to very high temperatures. Excessive heat causes film to buckle because of shrinkage at the edges. When severe, this distortion affects the ease with which the information can be taken from microfilms, either by projection (for reading) or by printing onto another film.

Silver-gelatin films that have been conditioned at a relative humidity of 50% or lower will withstand 121°C (250°F) for 24 hours without significant loss in readability or printability. At 149°C (300°F), severe distortion can occur in a few hours.

Films that have been conditioned at a relative humidity above 50% may show objectionable distortion in somewhat shorter times or at lower temperatures. Higher humidities, however, are undesirable for other reasons, as explained later.

Thermally processed silver films will build up background densities fairly rapidly at temperatures of 93°C (200°F) and above. At these temperatures, even a few hours will produce significant loss in readability or printability. At 149°C (300°F) or above, severe distortion can occur in a few hours.

Diazo films, while quite stable, contain dye images that can fade and/or discolor as a result of high temperatures. Kodak Diazo Microfilms can withstand a week at 93°C (200°F) without image loss. At 149°C (300°F) or above, severe distortion can occur in a few hours.

High temperature is the greatest enemy of vesicular film. Although Kodak Thermal Print Films can withstand 71°C (160°F) for several hours, high temperatures can cause a complete loss of images if care is not taken with regard to temperature control.

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D-31 June 2002

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Kodak D-31 manual Storage Vaults, Cabinets and Safes, Effects of High Temperatures

D-31 specifications

Kodak D-31 is a color negative developer that has garnered attention for its unique set of features tailored to meet the demands of both professionals and enthusiasts in the field of photography. Designed primarily for use with color negative films, Kodak D-31 is known for delivering impressive results in terms of color reproduction, contrast, and image sharpness.

One of the standout characteristics of Kodak D-31 is its flexibility in processing various types of color negative films. This developer can be used for a range of ISO sensitivity ratings, making it versatile for different photographic situations. Whether capturing landscapes, portraits, or street photography, D-31 ensures that the vibrant colors and subtle tones of each scene are accurately represented.

The technology behind Kodak D-31 incorporates a balanced mixture of color-forming agents and stabilizers that contribute to its reliability. The developer uses a carefully controlled chemical composition that ensures consistent performance with minimal grain, which is a critical factor for photographers who demand high-quality prints. The result is images that display fine detail and smooth transitions in color, which can be particularly important in post-processing and printing.

Kodak D-31 is designed for easy use, featuring a simple processing workflow that can be followed even by those new to film development. The Developer can be used with standard tanks and is compatible with both manual and automatic processing equipment. This ease of use makes D-31 an excellent choice for educational settings and home darkrooms, as it allows users to focus more on the art of photography rather than the technicalities of the developing process.

An additional advantage of Kodak D-31 is its ability to deliver consistent results across different batches, which is essential for those looking to maintain a cohesive portfolio. Photographers can rest assured that each roll developed will yield similar results, thanks to the high degree of control in the chemical composition and the assurance of quality that Kodak has provided for decades.

In summary, Kodak D-31 stands out as a reliable, versatile, and high-performance color negative developer that is well-suited for a variety of photographic applications. Its thoughtful formulation offers photographers the ability to capture and reproduce color with precision, making it a preferred choice for both hobbyists and seasoned professionals alike. With its blend of technology and ease of use, D-31 continues to be a valuable tool for anyone looking to explore the rich world of color film photography.