What are our firefighters Being Exposed to?
Firefighters face a hazardous mix of chemicals when exposed to smoke and other airborne particulates. Smoke itself is not a single substance, but a dispersion of gases, vapours, and particles that can carry hundreds of harmful chemicals, from PAHs and dioxins to phthalates, PCBs, PFAS, isocyanates, acids, and heavy metals. Many of these compounds are hydrophobic (resistant to water), sticky, and carcinogenic, and they bond tenaciously to plastics, rubbers, coated metals, and the multilayer textiles that make up turnout gear, hoods, gloves, and SCBA assemblies.
The occupational health detriment to our firefighters is now undisputed: firefighters experience elevated rates of cancer and other chronic diseases linked to repeated, low-dose, long-term exposure to these mixtures. Against that backdrop, the question is no longer whether we should insist on effective and reliable PPE decontamination; it’s how we establish a credible, national mechanism to assess, audit and verify the efficacy of cleaning functions, whether they be in-house, on-station or contracted to laundry specialists.
The Problem: Complex Dirt, Inconsistent Cleaning, Unverifiable Claims
Soot and smoke residues are chemically complex and physically variable. Their composition varies with fuel type and burn conditions; deposition varies across surfaces; and hydrophobic organics hitchhike on carbonaceous particles, which resist water-based removal via low-temperature cleaning. Conventional water washing at 40 °C delivers poor removal rates of smoke-borne dirt; studies repeatedly show limited removal of the 16 priority PAHs using standard or ‘test’ detergents and wash programmes, leaving visual staining and a lingering smoke odour.
Meanwhile, equipment and detergent vendors, as well as service providers such as contract launderers, market a range of methods, from optimised aqueous cleaning to liquid CO₂ systems, with different efficacies and trade-offs. Yet fire services lack a uniform, transparent way to verify whether a chosen process achieves the cleanliness levels claimed, on the products they use, under the financial and operational constraints they face.
Fire services are currently spending millions of pounds on subcontract cleaning of turnout kit as well as on machinery such as PPE spray washers and other laundry equipment, without fully understanding cleaning methodology or actual efficacy. There is a risk that many millions more will be spent over the coming years, with no evidence-based decision-making or method of independent assessment of manufacturer/contractor claims of performance.
The Answer: A National PPE Cleanliness Assessment Function
To verify PPE decontamination functions, the UK needs a coordinated, national audit tool that can standardise contamination and measurement of the removal rates of a given process and then publish results in the form of an annual audit assessment, a very powerful and potentially valuable set of data for Fire and Rescue Services.
At its core, the function would:
- Create a representative and repeatable contamination process - Samples of new or previously cleaned PPE would be consistently contaminated with real smoke and soot in a controlled environment. Critically, this means suspending samples or, perhaps more practically, swatches of material in live-burn smoke - not dosing with “pure” chemicals, so the hydrophobic, tar-like residues and particle-bound organics mimic operational reality.
- Analyse Levels of PAHs and other toxic compounds on the dirty samples, thus providing a ‘base’ point for verification after cleaning. This initial analysis should be done by accredited independent laboratories.
- Route those samples through actual cleaning functions - The same sets of identically contaminated samples would then be processed through the fire service’s real cleaning methods, whether in-house laundry, PPE spray washers for SCBA components, or subcontracted services, including any liquid CO₂ process.
Water temperatures, water hardness, chemistries, mechanical action, cycle times, load factors, and rinsing would be recorded to ensure reproducibility and adherence to the originally designed washing/decontamination process.
- Measure outcomes against claims and against expectations - Post-cleaning, the same accredited laboratories would analyse residues using robust extraction and analytical methods focused on a minimum of the 16 priority PAHs (with attention to the seven classified carcinogens), while providing scope for additional contaminants of concern (e.g., selected phthalates, PCBs, and markers of inorganic soot).
Where appropriate, acceptance thresholds should align to existing textile safety references such as OEKO-Tex 100 (e.g., ≤1 mg/kg for many PAHs). Results should quantify both per cent removal and absolute residual levels, with uncertainty bounds derived from replicate sampling.
This national function is not merely a lab exercise; it provides vital support to occupational health, monitoring of exposure rates and is of tangible value to procurement officers when tendering for either fully managed PPE frameworks or separate decontamination services. By issuing periodic, publicly available comparative reports, method by method, temperature by temperature, PPE type by PPE type, it would enable chiefs, procurement leads, health & safety officers, unions, and vendors to base decisions on scientific evidence, not solely manufacturers’ claims or supposition.
What We Already Know
Evidence from extensive field studies demonstrates that optimised aqueous decontamination at 60 °C using detergents tailored for hydrophobic soot and calibrated programmes for time, temperature, mechanical action, and thorough rinsing can reduce total PAH loads on textiles by 85–93%, frequently bringing individual PAHs below 1 mg/kg or even below reliable detection.
Similarly, well-designed PPE spray-washer processes for SCBA harnesses and masks have shown 87–97% reductions in total PAHs when preceded by effective pre-cleaning and application of appropriately formulated detergents. These results are promising, but they are yet to appear as specifications on any national tender.
The market remains confused in the face of competing claims of cleaning performance by LCO₂ specialists and those that advocate modern water-based methods of decontamination. The confusion is not helped by flawed analytical methods and inadequate data from the US’s NFPA cleaning requirements, which analyse only a narrow number of PAHs and work on an ‘average’ rather than ‘absolute’ removal measurement method – meaning that a 75% ‘pass’ could in fact mean 100% removal of one substance and only 50% removal of another. Another key flaw of the NFPA method is its use of artificial contaminants, which do not replicate real-life dirt, smoke and soot.
A UK formal assessment function would turn promising and, sometimes very affordable opportunities to improve firefighter health into proven and comparable processes, while exposing where results fall short or when washing processes underperform or have slipped from the original performance levels.
Liquid CO₂ (LCO₂) systems deserve nuanced evaluation within this framework. LCO₂ is a mild, low‑surface‑tension solvent that can be effective for hydrophobic organics within certain layers (e.g., membranes) and gentle on many materials, but it does not address water-soluble soils nor disperse carbon particulates; it is also expensive, complex, and is limited in its availability. A national programme would objectively show where LCO₂ or indeed any other ‘enhanced’ process adds value, as a supplement after optimised water-based washing, versus where well-engineered aqueous washing alone may deliver equivalent or better outcomes at far lower cost.
Proposed Principles for a National Assessment Programme
- Realistic contamination: Should use smoke from mixed-fuel live burns rather than dosing with a narrow range of neat chemicals. The latter yields misleading results. Particularly when comparing water washing and LCO₂ cleaning.
- Method transparency: Full disclosure of detergents and processes (at least by type/class and pH), temperatures, cycle designs, drum speeds, load sizes, and rinsing profiles.
- Material safety checks: Parallel assessments of wear and tear - because cleanliness is not success if the process accelerates degradation. Validate that optimised 60 °C programmes with appropriate chemistry can achieve low residue without unacceptable damage, and spotlight cases where 40 °C programmes rely on harsh boosters that can, ironically, increase wear and mask dirt and odours.
- Extensible analytics: Start with the 16 PAHs, then consider appropriate markers for other hazards and, where feasible, apply surface-swab methods for rigid components such as SCBA to complement textile analysis.
- Clear benchmarks: Report both % removal and residual mass per area or per mass against tiered thresholds (e.g., “Basic,” “Advanced,” “Best Available”) to drive continuous improvement while acknowledging operational constraints.
- Vendor‑neutral governance: House the function at national standards body(ies) or independent academic institutes with design input from FRSs, The Union, NFCC, and the FIA, along with the scientific community with expertise in surface chemistry. A final vital element is engagement with PPE manufacturers who must, as part of their product development process, be seen as responsible for producing products suitable for repeated decontamination with agreed degradation levels.
Why It Matters Now
Every fire leaves a residue. Without a national, repeatable way to measure cleanliness on the actual materials firefighters use, we rely on assumptions, marketing claims, and well‑meant but inconsistent practices. Establishing a national cleanliness assessment function will:
- Protect health: Reduce the risk of chronic illness via particulate exposure by making effective decontamination the predictable norm, not a ‘nice to have’.
- Guide procurement: Reward PPE manufacturers that develop products with smoother surfaces, fewer dirt-holding crevices, and that use materials that tolerate 60 °C aqueous cycles, whilst nudging standards and tender specifications toward suitability for decontamination as important as other performance attributes.
- Improve fairness: Give smaller services access to the same evidence as larger organisations, supporting informed choices whether cleaning is in-house or contracted.
- Accelerate innovation: Provide the comparative data manufacturers need to iterate chemistries, programmes, and equipment toward measurably better results.
A Call to Action
So, this is a call to action for the sector to pull together to build a national PPE cleanliness and decontamination assessment function that provides meaningful information to our fire services and puts independently produced data in the hands of fire services, who are, after all, charged with the responsibility of keeping their staff safe from all threats, whether physical or invisible.
Standardised contamination with real smoke, verifiable cleaning and decontamination through proven processes, and standardisation of measurements using accredited analytics. Publish the outcomes. Then repeat, so our firefighters can count on gear that is not just protective by design, but demonstrably clean and safe to wear for their next shout.