Wearer trials are key to PPE development

There was a time, still in the memory of many firefighters, when buying new PPE simply required a phone call or a posted order form to buy some extra wool tunics and PVC trousers.

In the years since then, protective firefighting clothing has evolved into sophisticated technical garments that incorporate different layers made up advanced high-performance fabrics.

What used to be an exercise in protecting from heat and flame is now a process that factors in design, comfort, breathability, as well as protection from blood, chemicals and particulates. The result is a range of different garments that will usually perform for seven to ten years.

As the procurement and evaluation process for new PPE has kept pace with the evolution of garment technology, effective wearer trials are now a fundamental part of a complex procurement process designed to buy the best protection possible for firefighters.

There are two key phases to wearer trials, the first is based on recognised compliance data and science and the second deals with the metaphysical in terms of human perception.

The starting point for any PPE procurement is to establish what the current baseline of performance requirement is and then undertake a risk assessment of current activities to identify if there are any changes that need to be factored in. This could be regulatory changes since the last procurement, operational variations, or wearer demographics. Then it is a case of removing any products that are not compliant with the developed tender specification.

So far so good, but the real complexity starts when a human dons the garments to provide wearer feedback. How this is approached can often be determined by budget. The most comprehensive methodology is a combination of wearer trials in realistic conditions recreated in a laboratory-controlled climate chamber and measured with sensors, followed by field tests that review feedback with users. The more users that are involved, the richer the data to inform decisions. The use of sensors can track core and skin temperature, heart rate, heat flow and impact on pressure points such as shoulders and knees.

At Gore, all GORE-TEX Moisture Barriers are extensively tested in lab conditions and out in the field to ensure that they are fit for purpose and performance claims are fully validated. That performance data is shared with fire and rescue services to inform their decision making.

The most important aspect of running wearer trials in the field is the need to develop a process that creates measurable responses and separates personal preferences. Perception, along with physics and physiology, is a key determinant in measuring comfort in a garment.

Without an effective and consistent way of gathering feedback and turning perception into meaningful data, you are just going to engineer a lot of noise. The firefighter’s brain is the richest source of data available, but only if it is collected in a way that sifts out that noise.

This is made no less complicated by human physiology. We are all physiologically different; some feel heat and cold more than others; some sweat more than others and some are naturally fitter than others. Evaluation and feedback forms need to be designed to take account of these factors.

How the collected data is managed is the latest consideration in the management of wearer trials. Every trial should now have a built-in policy and process for managing the collected data and the personal information of the participants that complies with GDPR rules.

The evolution of firefighter PPE has been driven by significant increases in knowledge and understanding collated from operational firefighting and wearer trials. This is the data that informs and drives innovation in the supply chain. That is why it is important to share as much of the data as possible, within commercially competitive limits, at the end of the procurement process. As well as validating the investment, it will gain buy-in from the wearers and management while supporting the development of enhanced PPE solutions for future generations of firefighters.

Gordon Burns

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