Advantages and challenges with using hypoxic air venting as fire protection

摘要

The use of hypoxic air venting system as fire protection is increasing and is sometimes used to replace traditional extinguishing systems. An oxygen level of 15% is generally used because a lower concentration could pose serious health risks. On the request of the Swedish Radiation Safety Authority, a literature review was conducted to determine advantages and challenges with the system and further research needs. The main advantages with a reduced oxygen environment are the reduced probability of ignition and lowered heat release rate. However, at 15% oxygen level, risk for fire still exists, and the system cannot be seen as an alternative to extinguishing systems. Reduced oxygen environment also results in higher production rates of soot and smoke, and there is limited knowledge regarding the effect of fuel configuration and fire behavior of products. In addition, a first evaluation of the test method specified in the hypoxic air venting standards was carried out through testing. The testing showed that the particleboard passed the test criteria at normal atmosphere even though it is commonly known that a particleboard burns in normal air. It is concluded that the test method has deficiencies, and there is clearly a need for development of the test method to guarantee safety levels.