CBRNeWORLD Gwyn Winfield looks at the developments in respiratory protection. Son of the Mask

Transcription

1 Gwyn Winfield looks at the developments in respiratory protection Most CBRN/NBC schools you visit boast a museum of sorts. Often this is a collection of material that would otherwise be in a forgotten storeroom (in case it was ever needed) but sometimes (like the Chemical Corps museum in Fort Leonard Wood) it is a significant effort at providing a useful history of the subject. The one thing that they all have in common is the collection of respirators, starting with the early box respirators all the way through to whatever their modern mask may be. There is something of the Ascent of Man about them, starting off with big, clumsy heavy systems, working through smaller, lighter, hotter respirators (full head respirator anyone?) to something that a member of the public will recollect from films about the future apocalypse. The abiding image is of an evolution; there are very few surprises in the incremental improvements that have been developed. Now, however, there might be an evolutionary change in respirator design akin to that first fish deciding that the dry, hot, airless place might be a good place to escape from predators. Part of this has to be down to the changing mission requirement within both the military and civilian sectors. Previously the military respirator requirement was based on the need to be able to provide adequate protection for days at a time and the ability to sight along your personal weapon. For the civilians it was either for short-lived tactical officer missions or as part of your 45-minute SCBA ensemble. There was a dichotomy between the military that required a large amount of respirators that had to be worn for (potentially) days and civilians who needed a far smaller amount of devices for approximately 60-minute mission sets (not including industrial hygiene). This shortage of choice continued to be driven by market forces (ie the military bought the bulk of respirators and therefore drove the design) until the mission sets started to change and blur. With the demise of the Cold War, the demand for respirators that needed to be worn for days at a time diminished (but never disappeared), the need for specialist skills increased, and the acceptance of a higher physical burden diminished. The first change in respiratory protection was the drive for PAPR respirators, that levels of physical fitness for some first responders/ receivers might not be as high as the military, and for those tasks with lots of standing around and little adrenaline (decon etc) there might be a need for a mechanised device that took all the burden out of breathing. While embraced warmly by the civilian sector, despite an initial lack of standards, they have not seen whole-scale use in the defence sector. At the other end of the spectrum was the adoption by the military of selfcontained breathing apparatus, previously a piece of equipment adopted only by fire hazmat crews, but now fairly ubiquitous across all CBRN responders. While it suddenly enabled a whole new mission set for the military it did come with some significant limiting factors: physiological load, noise and mission time. There have been some attempts within the SCBA (and wider PPE) community to deal with all of these limitations, increasing the amount of air in the tank, lowering the weight and making quieter systems. While these will no doubt continue at a slow, incremental pace the biggest change has been the development of hybrid systems that help manage these problems. Hybrid systems have the advantage of being able to switch between different modes, such as APR, PAPR or SCBA, with relative ease and with a high degree of protection. For example, the operative can be in transit to the mission in full PPE and on APR (saving his batteries), approach the objective on PAPR and then perform the mission on SCBA usually all achievable with the flick/twist/turn of a switch/dial/lever. Much like PAPR, and CBRN SCBA before it, technology leads the standard, so while currently individual components of the hybrid system (APR/SCBA etc) can have NIOSH or NFPA (for example) approval, the whole system can t as there isn t currently a standard for hybrid systems and this will be a challenge for grant-funded civilian procurement. The technology envelope is being pushed, and this will inevitably lead to standards. The first product in the hybrid stable was Wilcox Patriot system that had been designed for US naval special forces. Like many special forces systems there is little doubt that it is Gucci (or gold plated depending on your viewpoint) with a wide variety of features and options. Recent improvements have seen an eight-hour operational duration (presumably mainly off PAPR) for the Patriot, comes with PAPR, APR, SCBA or airline operation and additional cutting torch for breaching operations. While it is the original system it does come with a price-point that many find difficult outside of special forces. Coming a close second behind the Patriot is Osen Hunter s Shield. Those with long memories will remember Advanced Life Support Technologies, which was purchased by Osen Hunter in May 2012, but effectively the Shield is much the same. Much like the Patriot, it comes with APR, SCBA, PAPR and airline, and can operate for eight hours on PAPR, but the complete Shield system manages to be two pounds lighter. Both the Wilcox and Osen Hunter variants are able to be used with most modern respirators, but SCBA/respirator manufacturers are also picking up the baton with Avon, Scott and Draeger all offering comparable systems. Draeger offer their DHS 7000, as opposed to Avon and Scott which utilise their standard APR, Draeger have their DHR 7000, which they claim has 50 CBRNe WORLD August

2 Ready whatever the threat! Hybrid systems allow a smooth transition from APR to SCBA Avon August 2013 CBRNe WORLD 51

3 been designed specifically for the system and has enhanced comms. Scott have their modular respiratory protection system, which allows the customer to use whichever Scott APR they have, with a variety of Scott BA and PAPR. Avon have their ST53, which is unsurprisingly based on their M53 respirator, and uses their PAPR and Deltair SCBA. Draeger s DHS7000 comes in at 18lb, Avon s is slightly heavier at 18.75lb (though it is difficult to judge as there are so many variables), while Scott s has even more variables which put it in a range between slightly lighter and slightly heavier. There is still only a limited customer base for these products, ie those that have been SCBA trained and require a capability of this high order, but they are still an iterative improvement on what has been before. To try and see the future you have to start looking at some of the research that is being done. The EC has two (that I know of, with the duplication of effort in the EC, and their diabolical website, there could be a lot more), with FRESP looking at improvements in activated carbon and escape hoods and IFREACT looking at both a next-generation respirator and escape hoods (as well as other PPE and technological elements). The respirator from IFREACT, developed by NBC SYS, is likely to deliver a product that will be ahead of state of the art, and compete with products such as Scott s FRR or Avon s M50 series, and is likely to be available in the next 18 months. The developments that are likely to provide the vision of the far future are currently being worked on at US Army Natick Soldier Systems Center. We have looked at some of the work that Natick has been doing on a number of occasions, but perhaps the most pertinent to this article is the Future Chemical Biological Ensemble Ground Soldier System TDP (FCBE-GSS, see CBRNe World Autumn 2010). FCBE worked on two different respirator designs, the CB Prism and CB Ram. CB Prism (PRotective Integrated System Mask) sees a return to a blend of materials, an activated carbon material which covers the side of the face (ie not the oral/nasal cavity) and a more conventional butyl/polycarbonate material for the front of face. Prism is designed to be used only with a helmet, as there is no filter canister; the air would be drawn via twin activated carbon liners embedded inside the helmet with the air being drawn from the back of the helmet and expelled forward. The respirator has a ratchet mechanism for donning, and would be donned without the need to remove the helmet, which is a current problem, and through the integration into the protective ensemble lowers the thermal burden. Presumably one of the problems would be the life of the integrated carbon filters, since they would be in constant benign use, and as such need changing far more quickly than dedicated canister filters that can be sealed until needed (it also lacks the ability to do a hot swap). As opposed to the current generation of respirators, which are largely agnostic to which other elements of PPE you are wearing (with the exception of the head seal always a thorny issue) CB Prism is designed as part of an ensemble (CBCU and IPFS). So, for example, there is an activated carbon cowl neck integration. CB RAM (Rail Attaching Mask) is more of a conventional looking respirator than Prism; it has twin low profile conformal canisters and has a CONUSE of being an escape hood, rather than a true respirator. The advantage of RAM is that there is a helmet rail that the respirator clips into, which allows easy donning and doffing. This rail mounting is not unique to RAM, however; current aircrew respirators already feature this capability. The challenge for aircrew is fitting the mask in flight, which has meant (especially for Apache pilots with their targeting monocle) that at any state higher than MOPP1 the crew have needed to wear their respirator from take off even if their compatriots on the ground only need to carry theirs. Understandably this has not been popular. The Joint Service Aircrew Mask Hybrid systems reduce logistic drag and increase tactical efficiency' DoD 52 CBRNe WORLD August

4 Confidence to accomplish any mission Visit us at Booth #50 One system for every tactical CBRNe environment. FOR MORE, VISIT

5 (JSAM), designed especially for Apache pilots, and then rolled out across all aircrew, is able to be quickly fitted to the helmet with one hand. Mr Don Kilduff, JSAM Product Manager at JPM Protection, explained, Our primary design driver for the programme, besides compatibility with the helmet mounted display, was to providea don-in-flight capability which we satisfy with a dettachable faceplate. So for MoppII they put on the hood, hood ring and have the face-piece on a pouch on their vest, which they can easily don. That did drive an additional integration challenge, which was to stay within the realms of the helmet aperture. The unfortunate thing was two years after we rolled out the first design then PM Apache changed helmets, the new one had a smaller aperture, and we had to move some bits another half inch. We produced it in 2010, finished fielding in 2012, and we are now retooling for the new AH-64E model and new helmet. JSAM offers useful read-across for the next generation of helmet integrated respirator; where previously there would be fitting for a respirator and a helmet, now there needs to be an understanding that the fit for the helmet needs to be as accurate as the one for the respirator. Don Kilduff explained the situation that they had with the JSAM: Typically fitting an aircrew helmet is an iterative processs, involving multiple adjustments to achieve a comfortable fit. There is an expectation that aircrew can take their everyday flight helmet, put their mask on, put their normal helmet back on and have the same outcome. But the respirator fitting displaces it and it gets tighter. If it takes three weeks to get your helmet comfortable for your bare head, then why is it going to take less than three weeks with your mask? What all these elements hybrid systems and CB Prism etc show is that there is a drive towards modularity, to try and take some of the familiar elements of respiratory protection and incorporate them in other elements and make them smaller and smarter. There is a good chance that the nextgeneration respirator, in twenty years, will look very different from those that came before, but the lessons that Mr Kilduff offered for JSAM is a useful one; that as respirators get more advanced and shift burden onto other elements then those elements become more complicated, and pose a challenge unto themselves. For example, what soldier/first responder wants two helmets, what happens when a round/brick penetrates the helmet lining containing the filters, what happens to airflow when the individual is prone (in a firing position)? As the visit to the CBRN museums show, this is not the first time that respirator design has faced similar problems, and no doubt as new offensive agents are invented that there will need for other protective factors currently unknown to be incorporated in the future too!