Breakopen and Cost vs. Wearlife Discussed at Round Table

DuPont hosted a Round Table Debate at Nottinghamshire Fire and Rescue headquarters to encourage a discussion about topical issues regarding PPE in the Fire and Rescue sector.

The aim of the round table debate DuPont organised was to open up the discussion about personal protective equipment (PPE) and help fire fighters to understand and make better decisions related to protective equipment.

The debate was attended by a panel of leading fibre manufacturers, weavers, garment manufacturers and Chief Fire Officers who answered questions posed by Fire Times’ readers around three topics – heat stress, breakopen and cost vs wearlife.

This, the second part of the round table debate, reports on the topical issues about breakopen and cost vs wearlife.

The participants included:

  • Frank Swan (FS) , Chief Fire Office at Nottinghamshire Fire and Rescue Service
  • Gary Philips (GP), Deputy Chief Fire Office at Warwickshire Fire and Rescue Service
  • Mark Drysdale (MD), Commercial Manager – Protectivewear Fabrics at Heathcoat Fabrics
  • Symon Clifford (SC), Chief Fire Officer at Bristol Airport Fire Department
  • Charlotte Brandt (CB), Sales Manager at Hainsworth
  • Richard Ballheimer (RB), Service Delivery Manager at Lion Apparel
  • Zoltan Nahoczky (ZN), Marketing Manager at DuPont Protection Technologies
  • Ian Mitchell (IM), Joint Managing Director, Bristol Uniforms
  • Anthony Norbury (S1), Retired Fire Officer, Round Table Chair
  • George Farenden, Consultant at DuPont
  • David Holden, Fire Times

Nottinghamshire round table debate part 2: breakopen and cost vs. wearlife

S1     Let’s debate “breakopen”. This is a term used to describe the functionality of Nomex® when it’s exposed to fire. The fabric reacts, carbonizing, shrinking and thickening as it absorbs the heat and it is this reaction that contains the heat and prevents the fire fighter from receiving burns. The process can be aligned with that of a modern car that is designed to collapse on impact in order to protect the occupants. This characteristic is often misunderstood and misquoted when it is actually a life saving feature.

CB    When Nomex® carbonises it’s absorbing the heat. It’s translating that heat into a protective char barrier. So what you’re doing is preventing that heat from entering the garments. If you don’t form a char barrier, where does the heat go? Also the carbonised layer does not crumble and go brittle until it cools. So from a protecting point of view I think it’s a very interesting way of nullifying heat in a garment and not moving it through to the wearer. So I see it as a benefit of kit rather than a hindrance.

ZN    There is a timing aspect. Initially there is the big heat impact and the fabric remains flexible and has physical integrity. It only starts to crumble when it cools down. By that time the garment should be removed from the fire fighter when he or she is outside of the hazardous area, because otherwise all the energy accumulated in the garment would burn the fire fighter.

CB    But has there ever been an issue with breakopen in the field?

FS     Not to my knowledge. It’s very easy. We have to trust the technology, and in selecting the PPE we carry out as robust a process as possible.

GP    I certainly don’t have any issues.

CB    No. I think breakopen is a very emotive subject. It’s very easy, in lab and test conditions, to misconstrue what is happening, I think that the true test is out in the field and to the guys wearing it, it’s not an issue, it’s not something we see.

FS     I think one of the problems here is the terminology “breakopen”. It makes it sound as though the whole garment’s got a gaping hole in it which of course isn’t the case. There’s still an amount of thermal protection there. The characteristics of Nomex® and this carbonising effect suck in the heat and stops it going anywhere else through the garment.

CB    Neutralizes it.

FS     So in that sense it’s doing its job. Then later it crumbles when it cools, but you’re not going to hang around when you’re in that situation, you’re going to get the hell out and get the garment off.

S1     I think the question is, “has breakopen occurred in the British Fire Service or Airport Fire Service anywhere?”

RB    Certainly in the ten years I’ve been with Lion, I’m not aware of a single garment that’s broken open, not a single one.

S1     Our first question is from Brett Egan, Development Manager, Operation and Assets Kent Fire and Rescue Service: “Breakopen is a physical characteristic of meta-aramid materials and it is debatable that it is a life saving feature. If a garment breaks open following the exposure to fire, presumably the fire fighter is still in the risk area. What reduction in performance of the garment is now occurring?”

CB    This is the common misunderstanding between carbonisation and breakopen. Carbonisation happens with the absorption of the thermal energy. Breakopen can happen when the fabric is cold, and moved because it’s brittle. So breakopen and carbonisation are not the same thing and one doesn’t necessarily follow the other. For example, breakopen would not happen in a hot environment.

ZN    Carbonisation occurs when the meta-aramid absorbs the heat and the temperature rises to 400-500 degrees or higher. The fabric remains warm and flexible, but you can see that it’s thickening. You need much more energy because the fabric itself uses up heat and converts its molecular structure – that’s carbonisation. Afterwards, when the garment cools it can break. That’s the two major steps in this process that affects only the outer layer.

MD    Breakopen as a term is universally used and I think you’re right in saying maybe its perception is different to different people at different occasions. DuPont uses the term breakopen in guidelines for using Nomex®, and they add a content of Kevlar® to the blend rather than just Nomex® to help give the fabric strength and minimise the amount of breakopen.

S1     Shall we move onto initial cost versus wear life cost?        “How much does this really matter to brigades today? It’s extremely well reported that all brigades regardless of size or location are having to absorb tremendous project cuts and purchasing turnout gear is likely to be one of the most expensive exercises a brigade will experience. However, is it better to buy wisely initially and reap the benefits of a longer lasting kit, therefore saving money in the long run? Some brigades are saying that their main focus is to purchase a kit that conforms with EN469, but are highly competitive pricing and lower wearlife costs confusing the issue?”

GP    I want the best kit I can get to protect fire fighters, because their safety is paramount. We have to face budget cuts, but nonetheless, fire fighter safety is absolutely paramount and on that basis I would make sure that we buy the best kit; they would get the best protection and then, if one of those spinoffs was the best value for the Fire and Rescue Service, then that’s fantastic.

RB    The initial cost is one thing, but if you buy something that gives you a good level of protection, but doesn’t last very long, then you might have to buy it two or three times, whereas through controlled care and maintenance you can extend the wearlife.

FS     It’s a difficult one, but I mean, if I was a purchaser in a brigade, obviously I’d want to look at the whole life cost because it’s a fundamental part. The initial issue is one thing, but if you’re expecting kit to last eight years, there’s an awful lot of replacement kits going to come in the meantime, which has also got to be taken into account. The significant point here is that it is one of the most expensive outlays we have. We are an average size service and our last procurement was just touching £1,000,000 and then we try and extend the life by adding on cleaning and maintenance. We can look at whole life costs and then select what’s the best option, but rest assured we don’t start from the point of cost. We start from the point of selecting PPE which we think is the best available for our staff and then we look at costs. It’s driven by the primary safety role.

ZN    If kit is more durable, it will obviously last longer and this is where the blend of a para-aramid, Kevlar®, and meta-aramid, Nomex®, is important. In terms of abrasion resistance the more Kevlar® or para-aramid a weaver puts in a fabric for tear strength, the less abrasion resistance the fabric may have, decreasing overall wearlife. That’s why we advise to keep the Kevlar® content low to moderate, just to make sure that the wearlife cost is manageable and the life of the garment is longer. Kevlar® can add a lot of strength, but its abrasion resistance, when incorporated into woven fabric in high concentrations, can be counter-productive, so Nomex® can really help to increase durability. There is a lot of innovation going on with garment manufacturers and weavers; they can combine Nomex® & Kevlar® fibres and come up with new weaving technologies, new design ideas, and improvements to the care of the garment that will increase wear-life .

FS     Innovations and improvements don’t make what you’ve got bad.

S1     Exactly, yes. I think evolution is the key word rather than revolution, and that needs to be emphasised because that will reassure a lot of chief fire officers and other managers of brigades that they’re not going to be chasing things that cost loads of money in the very near future.

Click here to read part one, reporting on the debate around heat stress.