Why Firefighting Hoods must have Particulate Protection
Protective hoods are one of the most critical components of firefighting turnout gear. While other, heavier components of the firefighting outfit provide effective head-to-toe protection, areas of vulnerability persist. The head, face and neck are particularly prone to exposure, and studies have shown that ‘carcinogen-carrying soot and other particles can collect in significant quantities’ [1] in these areas.
The effects of smoke and particulate matter on the body are linked to dramatically higher rates of cancer diagnoses among firefighters. Research by the U.S. CDC/National Institute for Occupational Health and Safety (NIOSH) has revealed that ‘Firefighters have a 9 percent higher risk of being diagnosed with cancer and a 14 percent higher risk of dying from cancer than the general population.’ [2] Further studies have confirmed that the ‘neck and jaw areas are most vulnerable to smoke particle exposure’ [3] which is why protective hoods are so important. However, these same studies have also shown that protective hoods are ‘the most penetrable piece of equipment.’ [4] in a firefighter’s ensemble. While traditional, knitted protective hoods do provide increased thermal protection and flame-resistant properties, they have limited protection against soot and particulate matter.
This presents a fresh challenge for the industry, to create a protective hood that not only provides thermal protection, but also acts as a barrier to the particulate matter and toxins which can collect on the skin. With this increased knowledge about the risk of skin absorption of dangerous smoke particles Firefighters must now demand more effective protection. As a result, the quality of protective hoods has increased dramatically.
Particulate protection hoods ‘act as a filter to reduce firefighters’ exposure to persistent fireground carcinogens and other contaminants’ [5] which can block particulates as small as 0.2 microns. To illustrate the scale a 0.2-micron particulate is about 500x smaller than a strand of hair.’ [6] Particulate matter consists of a mixture of extremely small solid and liquid particles. The toxicity of the particulates depends on how small they are, and ‘how deeply they are able to penetrate the respiratory tract.’ [7] WHO studies estimate a shocking ‘0.5% increase in daily mortality with exposure to particulates with a size of 10 microns or smaller.’ [7]
Particulate protection hoods in Europe must be certified to the ‘CEN, EN 13911:2017 Protective clothing for firefighters – Requirements and test methods for fire hoods for firefighters.’ [8] The latest edition requires specific testing for particulate filtration capabilities of protective hoods. Results must reach at least 90% filtration efficiency for certification. Manufacturers must also consider the weight of protective hoods, the ability of firefighters to hear through this extra protective barrier, as well as the durability of the product.
Modern Protective hoods use a fabric comprised of aramid fibres which are ‘synthetically produced fibres which are inherently heat- and flame-resistant and maintain these properties at high temperatures.’ [9] This provides thermal protection for the firefighter’s head and neck region. Particulate protection hoods add a further layer beneath the first layer to further enhance the thermal protection of the product and protect against particulate matter. Depending on the manufacturer, the particulate-blocking layer may cover the entire head and neck areas, including the top of the head under the helmet, or only the neck region, including the ears.
The industry has rapidly responded to the growing evidence linking particulates to increased cancer rates in firefighters, working in tandem with fabric and fibre manufacturers to develop innovative new products, specifically designed to filter particulates. These hoods are designed to be worn under the helmet and collar and specifically offers increased protection to the neck and the upper jaw areas, the regions of the body which are particularly vulnerable to soot and smoke particles.
While particulate protection is a necessary addition to Fire Hood design, this cannot come at the expense of overheating, especially in trying circumstances when the wearer will already be under increased strain. Some designs combat this issue with heat stress by focussing protection on the most vulnerable areas but often without protection at the back or the top of the hood. While this is effective at reducing heat stress it does of course come at the cost of reduced particle protection in those areas.
Many brands now implement the DuPont™ Nomex® brand fiber, an inherently flame-resistant material and will not melt, drip, or support combustion in the air when exposed to extreme heat and flame. [10]
Du Pont’s new, innovative Nomex NanoFlex particulate barrier has been specifically developed to prevent contamination from particulates. The new material is highly heat and flame-resistant with excellent particle filtration capabilities, but is also highly breathable, very thin, and lightweight, which is crucial for allowing both heat and moisture to escape. These qualities are essential for preventing heat stress and maintaining comfort in extreme environments.
S-GARD’s NANO FLAME PROTECTION HOOD utilizes the DuPont™ Nomex® Nano technology, which was developed to address this rising problem of heat stress, which is the source of more firefighter injuries than any other single factor. Nomex® Nano is thinner than other materials but still provides effective protection from smoke and soot particles. This allows the S-GARD Flame protection hood to provide complete coverage without any open spots as the entire head is covered.
[The FireHunter® Particulate Blocking Fire Hood] is another effective option which is backed up by Hunter’s head-to-toe PPE, care & maintenance solutions which were ‘recognised by the British Safety Industry Federation (BSIF) as overall winner in the safety solution category in 2020.’ This increases its product’s effective longevity dramatically, improving long term health outcomes for firefighters.
The industry now recognises that particulate protection is a necessary addition to Fire Hood design, this cannot come at the expense of overheating, especially in trying circumstances when the wearer will already be under increased strain. This is where BarriAire™ Gold Particulate Barrier Hoods from PGI Safety are particularly effective. They are widely accepted as some of the most protective and breathable particulate hoods on the market. Some even suggest that ‘this is the first particulate barrier hood that feels barrier-less!’ [12]
MSA Bristol offers several Particulate Protection Hoods which utilize Nomex NanoFlex technology, which combines superior particle blocking performance with increased elasticity while retaining the thin and lightweight properties of Nomex Nano, to maintain comfort under stress. These products are highly flame-resistant with excellent particle barrier performance, but also are thin and lightweight, to maintain comfort during stressful circumstances.
While the continuing technological advances in particulate filtration are certainly ground-breaking, they can only go so far towards reducing a firefighters’ exposure to soot and smoke particulates. Experts advise that ‘risks can be further reduced if exposed PPE is removed promptly and carefully following an incident, and then professionally decontaminated.’ [13] A consistent cleaning process must take place after every exposure to ensure the product maintains its effectiveness.
The new particulate protection hood products may be more expensive initially, due to the increased complexity of their construction, but their lifespan, effectiveness, and increased resistance to tough environments will reduce their overall cost in the long-term. Regular usage of cleaning and decontamination services will help to further reduce the impact of this initial outlay over time and greatly increase the efficiency and longevity of the product.
Why Firefighting Hoods must have Particulate Protection is written by David Blackbourn Contributing Editor at Marcus Media.