Movie Terms Wiki Filmmaking

Nitrate Base

A highly flammable film stock base made from cellulose nitrate used until the 1950s.


Nitrate Base

Definition and Properties

Nitrate base refers to motion-picture film stock whose support layer is composed of cellulose nitrate. Renowned for its excellent image quality and flexibility, nitrate base also exhibited extreme flammability and chemical instability.

Historical Usage

From the 1890s through the early 1950s, nitrate base was the standard for 35 mm theatrical and documentary films. Its superior light transmission and mechanical strength made it indispensable for early camera and projector technologies.

Risks and Incidents

Nitrate film can decompose, releasing nitric acid and turning into a powdery residue. In poor storage conditions, it may self-ignite at around 41 °C, fueling rapid, oxygen-rich fires. Major archive fires—such as the 1937 Fox vault fire—destroyed countless silent-era films.

Transition to Safety Film

Due to its hazards, nitrate base was gradually replaced by acetate “safety” film after World War II. Many surviving nitrate prints require specialized vaults and handling protocols, and archives often transfer content to stable media to preserve cinematic heritage.


© 2026 What's After the Movie. All rights reserved.

Privacy Policy