As firefighters grow more concerned about dangerous contaminants on the fireground, many have turned to particulate barriers.  

Particulate barriers are an optional add-on to turnouts that provide an extra coat layer with particulate blocking technology at the interface between the jacket and pants.  While they can offer additional protection, they make turnout coats much less breathable.  

When turnouts are less breathable, they can trap heat inside and don’t allow your sweat to evaporate and cool down your body. That contributes to overexertion and heat stress—the number one cause of LODDs.  

Fire-Dex is committed to firefighter health and safety, whether that’s protection from flames, contaminants, or heat stress. We provide gear to help firefighters be better on the fireground and healthier at home.  

Many have wondered if engaged SCBA straps could provide the same levels of protection as particulate barriers, without the added risk of heat stress. The theory is that SCBA straps at the waist are tight enough that they would provide sufficient sealing to keep out particulates at the coat/pant interface.  

That’s why we asked RTI International, a nonprofit, independent third-party testing laboratory, to test the efficacy of particulate barriers.  

They conducted specialized testing at their particulate research facility to test the particulate-blocking efficacy of a properly donned SCBA compared to an additional particulate barrier.  

The Tests  

RTI performed three tests, using a similar process as the well-known FAST study.  

For each test, the tester donned full head-to-toe Fire-Dex PPE: 

• AeroFlex turnouts 
• H41 Interceptor Hood (particulate blocking) 
• Dex-Pro Gloves 
• FDXL200 Boots 
• Fire-Dex Helmet 

The only difference between each test was a particulate barrier or an SCBA:  

1. Particulate barrier and SCBA  
2. No particulate barrier and SCBA  
3. Particulate barrier and no SCBA

The tester entered a room filled with a precise level of particulates and performed a series of actions (e.g., squatting, lifting arms, walking) for two 10-minute cycles. The tester exited the chamber and carefully doffed the equipment.   

The Results 

To measure the results, researchers used a special camera to analyze the amount of particulate matter on the tester’s skin after doffing their gear.  

They found that when an SCBA is properly worn and secured, a particulate barrier does not offer any additional protection against particulates on the torso compared to gear without a particulate barrier. This is because the SCBA straps tighten the turnout coat, creating a sealing effect. 

The results also showed that particulate-blocking hoods, as well as particulate barriers in turnout pants, provide increased protection.  

Test 1: Particulate Barrier and SCBA

Torso show no signs of particulate exposure  

No exposure on thighs or armpits and sides show AeroVents adequately block particulates 

Test 2: No Particulate Barrier and SCBA

No exposure on torso 

Legs show exposure, indicating that pant particulate barriers provide protection

Test 3: No Particulate Barrier and SCBA

No exposure on neck or shoulders highlights the effectiveness of particulate blocking hoods  

Minor exposure on the back shows SCBA provides additional particulate blocking 

Particulate Protection 

Beyond the particulate barrier finding, the test also demonstrated the efficacy of a particulate blocking hood.  

On each test, there was virtually no contamination found on the tester’s head and neck area, clearly showing the value of a particulate-blocking hood.  

The test also showed that the AeroVent Technology in AeroFlex turnout gear provides incredible particulate blocking capabilities. These vents use innovative design techniques and materials, functioning as one-way vents that release hot air from inside your turnouts and prevent particulates from getting in. Breathable fabric lets that hot air out and particulate-blocking technology stops contaminants from entering. 

The Bottom Line 

Third-party testing demonstrates that an engaged SCBA can provide similar protection to a particulate barrier in the pant/jacket interface. While the test demonstrated the benefits of extra particulate blocking in turnout pants, it showed that they may not provide any additional protection in the coat. 

Turnout coats cover the core of your body, making increased breathability crucial. Core body temperature increases are associated with significant health issues, from hearing issues to cognitive decline.  

Particulate barriers affect the natural evaporative cooling process, where fresh air can replace the hot, saturated air trapped in turnouts. Without the barrier, this process is much more efficient and sweat evaporates more quickly. 

In general, SCBAs are always worn on structural calls where particulate blocking is often used. That means the greatest protection against particulates isn’t an added option, but a tool that firefighters already use every day. Simply put, particulate protection at the jacket/pant interface can be achieved with gear that’s already being worn on structural calls—without the need of an extra layer.  

Fire-Dex Means Safety 

Fire-Dex is committed to the safety of firefighters everywhere. That’s why we continually innovate our materials and designs to provide the most breathable fabrics and most breathable turnouts.  

We’re also committed to backing up everything we say and do with independent research. We stand behind our products because we believe that our know-how can help keep you safer on the fireground and beyond.