The effectiveness and safety of fire hoods

To avoid confusion, the terminological convention which emerged within the fire service during the life of the project is adopted in this report. The term ‘anti-flash hood’ will therefore be reserved for hoods meeting the E9 specification. Balaclava-style hoods will be referred to as Tire hoods’.In recent years, there has been a growing interest within the fire service in the use of balaclava-style fire hoods as an alternative to, or replacement for, the E9 specification anti-flash hood. This report describes the results of a project, commissioned by the Home Office, to investigate aspects of the use of fire hoods by operational firefighters. It examined elements of the effectiveness of the fire hood in terms both of heat exclusion (particularly radiant heat protection) and heat retention. It also addressed safety issues, notably concerns expressed by an appreciable number of firefighters that they would be more isolated from their working environment whilst wearing such hoods and, possibly as a result, that wearing a hood would engender different attitudes to firefighting risks, resulting in a detrimental effect on behaviour.The project firstly demonstrated an undoubted need for some such protection as shown by the high proportion of reported burn injuries involving injury to those areas of the head and neck which were usually exposed, but would have been covered by a fire hood if worn. It also showed that, although there were some specific design shortcomings with some fire hoods, the head coverage and fit provided by most hoods was adequate as was the level of radiant heat insulation. Despite this insulative effect, the impact of wearing a fire hood on heat retention and body temperature was not significant. Although the head is potentially an efficient avenue for heat loss, the existing coverage by helmet and BA face mask is such that the additional coverage by a fire hood does not have any real effect.Another safety concern addressed was that of heat awareness and the related issue of heat flow around the head and up into the helmet. Trials showed that firefighters are not particularly good at accurately assessing the environmental temperature and that wearing a fire hood did not cause any significant deterioration in their abilities in this respect. Laboratory tests showed how a fire hood could insulate the scalp from heat flowing into the helmet head space. There were however indications that the fabric skirts fitted to the rear of many modern styles of helmet could channel heat into this space, potentially causing greater thermal discomfort.Because fire hoods cover the ears of the firefighter, it has been suggested that this might have a potentially hazardous impact on hearing ability. The project examined two aspects of this. Firstly, it quantified the noise attenuation characteristics of a variety of hoods, showing these to be negligible. Secondly, it looked at the impact of the fire hoods on sound location, systematically evaluating the ability of a wearer to identify the direction from which a DSU noise was coming from against a background of fireground noise. Again, the results showed this concern to be unfounded. However, a novel, wrap-round, design of helmet, which was investigated as part of this element of the study, did have some detrimental impact both on noise attenuation (there was some evidence of a resonance effect within the head shell at certain frequencies) and on sound location.Finally, observational trials of firefighters wearing fire hoods during a live-fire, search and rescue exercise, did not show any systematic impact of fire hoods on safe working practices either by staying in hot areas for longer or by neglecting standard safety procedures. What became apparent during these exercises however was a considerable variety of approaches between different brigades. This suggests possible benefits could be obtained from standardising between brigades on best practice in training.