Excerpts from FireRescue1.com:
In February 2014 we wrote that protective hoods are the most vulnerable area of the firefighter’s ensemble. That’s because hoods lack any type of barrier characteristics to keep out the superfine particles that absorb a variety of hazardous chemicals including carcinogens.
This shortcoming was coupled with NIOSH studies and other research showing carcinogen buildup on firefighters’ skin, particularly on the neck and face areas unprotected by the SCBA face piece. Further, that skin absorbs chemicals easily around a person’s jaw line led to the obvious conclusion that current-day hoods have little effectiveness in keeping out soot.
In January 2015, we assisted the IAFF with a study to show how much particle penetration takes place throughout the entire structural firefighting ensemble. After that, there could be no doubt that the hood is one of the serious gaps in firefighter protection that needs to be solved.
An overwhelming number of firefighter hoods consist of two layers of knit material fashioned into a sock-like hood that stretches over the firefighter’s head with an opening for the SCBA face piece and bib that is supposed to stay tucked inside under the top of the coat.
The current requirements in NFPA 1971 considers hoods an interface device for providing thermal protection in areas where other ensemble elements do not always provide complete coverage, such as the SCBA face piece, helmet ear covers and coat collar. Yet as the firefighter moves, the hood shifts and leaves the interface areas exposed to the hostile environment.
When the revision process for the NFPA 1971 standard began, a specific task group was charged to come up with possible ways for minimizing firefighter exposure to the carcinogens and other harmful substances contained in soot. One way to achieve complete particle blockage could be to install a moisture barrier as part of the hood composite, similar to the way garments use the same barrier materials.
The increased layering of the hood and the further encapsulation of the head pose additional stress to an already physiologically challenged
first responderfirefighter. We therefore suggested that a total heat-loss test be applied to these newly reinforced portions of the hood at levels far above those required for garment composites. In this way, the maximum amount of heat stress relief could be provided without compromising the particle holdout capabilities of the new hoods.These proposed requirements will not be adopted in one form or another until mid-2017. Meanwhile, several manufacturers and fabric suppliers have been working on prospective hood products to reduce firefighter exposure to soot and the adsorbed chemicals contained in smoke particles. These products encompass a variety of new hood designs and combinations of different barrier materials, including both new particle filter layers as well as conventional moisture barriers.
All of the new products, many unveiled this past spring, are certified to current requirements in NFPA 1971 as regular hoods. The new particle barrier hood criteria are not finished. As would be expected, the new hood products are more complex, use new materials and are consequently more expensive. The fact that these hoods are more costly means that fire departments will expect the hoods to stay in service longer.
This brings into question the hoods’ durability over an extended period with multiple cleanings and how well the particle-blocking capability and relative fit will be maintained. And since the new hoods incorporate an additional layer, they are also somewhat heavier and will have higher thermal insulation than conventional hoods. The greater levels of heat protection means firefighters will perceive heat to a lesser degree than the already do, which can be good or bad depending on how firefighters are trained to react to heat.
The industry still has to work out these issues, particularly as the new version of NFPA 1971 comes to fruition. In minimizing exposure to carcinogens, PPE use is only one of several approaches needed to solve this problem.
