Nitrate Vault

Cages for Flaming Ghosts

A Nitrate Vault is not merely a storage room; it is a purpose-built containment facility engineered to manage one of the most beautiful and treacherous materials in film history: cellulose nitrate. Used as the standard motion picture film base from the dawn of cinema until the early 1950s, nitrate film is prized for the luminous, silvery quality of its black-and-white images. However, it is also a ticking time bomb. As it ages, it chemically decomposes, releasing oxidizing agents that can cause it to spontaneously combust at temperatures as low as 106°F (41°C). Once ignited, a nitrate fire is nearly impossible to put out, as it produces its own oxygen and can even burn underwater.

The Architecture of Safety

The tragic history of devastating archive fires in the 20th century, which destroyed an estimated 75% of all American silent films, led to the development of strict architectural and safety standards for storing this material, primarily outlined in NFPA 40: Standard for the Storage and Handling of Cellulose Nitrate Film. A modern nitrate vault is designed with a single, overriding principle: to contain a fire in one location and prevent it from spreading to others.

Key design features include:

• Cellular Structure: Rather than a large warehouse, nitrate vaults are composed of many small, individual rooms or ‘cells,’ typically made of reinforced concrete. Each cell holds a limited quantity of film, minimizing the potential loss in a fire.
• Isolation: The vaults are often housed in a separate, isolated building away from main archives and work areas.
• Fireproof and Explosion-Vented Construction: Each cell is equipped with heavy, fire-rated steel doors. The structures are designed to vent the force of an explosion upwards or in a safe direction, away from personnel and other cells.
• Sprinkler Systems: Every cell is fitted with a deluge sprinkler system designed to cool the surrounding environment and prevent fire from spreading to adjacent cells, even though it cannot extinguish the nitrate fire itself.
• No Active Utilities: To prevent ignition sources, there is typically no electrical wiring, lighting, or heating inside the storage cells. The rooms are designed for storage only, not for people to work in.

The Preservation Imperative

Today, the world’s remaining nitrate film is a priceless and finite cultural resource, encompassing the foundational works of cinema. Major film archives like the Library of Congress Packard Campus, the George Eastman Museum, the UCLA Film & Television Archive, and the BFI National Archive operate these specialized vaults. The preservation workflow for nitrate film is a race against time: archivists must carefully inspect the film for signs of decay (such as a noxious smell, sticky texture, or brownish dust) and prioritize the most endangered reels for immediate digitization or photochemical duplication onto modern polyester safety film. The nitrate vault’s function is to slow this inevitable decay and safely house the material until it can be preserved, protecting both our cinematic heritage and the archivists who care for it.