Background: Lowering the level of oxygen is now being widely used in the United Kingdom and Europe as an alternative fire suppression system, but is not yet approved by the National Fire Protection Association for use in the United States. There is often confusion between the terms anoxic and hypoxic. Anoxic refers to the complete removal of oxygen and for the Library (due to limitations of monitoring equipment) this is considered less than 0.5% oxygen. Hypoxia refers to reduced oxygen levels, below that of ambient air which is 21% oxygen.
Contributing Study:
British Library Low Oxygen Case Study [PDF 794 MB, 30p].
Strlič, M., Cigić, I. K., Možir, A., de Bruin, G., Kolar, J., Cassar, M. The Effect of Volatile Organic Compounds and Hypoxia on Paper Degradation. Polymer Degradation and Stability 96 (2011) 608-615.
Project Description: Staffs in the Preservation Directorate are reviewing current literature and the availability of new equipment in this area, to assess the potential for using hypoxic fire suppression in display cases at the Library of Congress.
Outcomes/Findings:
- Available systems essentially reduce the level of oxygen below 16%, the level at which flames cannot ignite.
- Research into the benefit of reduced oxygen levels on preservation of Library collection materials is under investigation, and has been assessed for paper degradation (Strlic et al.).
