Fire Protection Research Foundation report: “Review of Oxygen Reduction Systems for Warehouse Storage Applications”
Authors: Patrick van Hees, Lund University, Lund, Sweden; John Barton, Lund University, Lund, Sweden; Martin Nilsson, Zurich Insurance plc, Stockholm, Sweden; and Brian Meacham, Meacham Associates, Shrewsbury, MA, USA.
Date of issue: November 2018
Oxygen reduction (or hypoxic) systems are being used in warehouse facilities as an alternative to sprinkler protection. The basic principle of operation is to displace the ambient oxygen in an enclosed environment with one or more nitrogen generators. Two test methods that are available today to determine the reduced oxygen level needed for property fire protection purposes include: VdS 3527en (2007), Oxygen Reduction Systems Planning and Installation, and EN 16750:2017 E, Fixed firefighting systems – Oxygen reduction systems – Design, installation, planning and maintenance (replaced British Standards Institution PAS 95 (BSI PAS 95), Hypoxic Air Fire Prevention Systems).
Concerns with the test methods in VdS 3527 and BSI PAS 95 for determining ignition thresholds have previously been expressed by others. The conclusion is that the reduced oxygen levels established by these two tests are only valid for the tested conditions and may not represent real-world conditions.