Liquid CO₂ Firefighter PPE Decontamination: How It Works
Short answer: Liquid carbon dioxide (CO₂) decontamination is a specialized cleaning process that uses carbon dioxide held under pressure in liquid form to treat contaminated protective equipment. The system brings the cleaning medium into contact with the gear to help remove targeted contaminants. The process, equipment, and demonstrated results vary, so fire departments should evaluate the specific technology, supporting tests, and applicable PPE-care requirements before choosing a provider.
A fire is out. The crew is back at the station. The gear comes off, the apparatus gets checked, and everyone starts thinking about the next call.
But the work of managing contamination is not necessarily finished when the emergency ends.
Firefighter turnout gear can carry substances from smoke, burning materials, and other incident exposures. Routine washing is an essential part of equipment care, but departments may also need to consider whether additional cleaning processes are appropriate for their gear and exposure profile.
Liquid CO₂ decontamination is one option attracting attention in the fire service. Understanding how it works, what the technology can offer, and where its limitations lie helps department leaders make informed decisions.
What is liquid CO₂ decontamination?
Liquid CO₂ decontamination uses carbon dioxide maintained in a liquid state under pressure as a cleaning medium.
Carbon dioxide is familiar as a gas at ordinary room conditions. Under the right pressure and temperature, however, it can exist as a liquid and be used in specialized cleaning equipment.
In these systems, the liquid CO₂ is brought into contact with the items being treated. The process is designed to help dislodge or dissolve targeted contaminants and carry them away from the material being cleaned.
Unlike conventional water-based laundering, the cleaning medium is carbon dioxide rather than a water-and-detergent mixture. The process takes place inside specialized equipment designed to control pressure, circulation, and other operating conditions.
Cool Clean Technologies manufactures liquid CO₂ cleaning systems, including equipment intended for firefighter protective gear. Its technology overview explains the basic cleaning process and how the system manages CO₂ during treatment. Learn more about liquid CO₂ cleaning technology from Cool Clean.
How does the CO₂ cleaning process work?
The details depend on the particular machine and treatment process, but several basic steps help explain the technology.
1. Gear is prepared for treatment
Before equipment enters a specialized cleaning system, the service provider must identify what is being treated and determine whether the items are appropriate for that process.
Firefighter PPE includes different materials, layers, closures, and components. A coat, pair of pants, hood, and gloves may have different care considerations.
The provider should follow the equipment manufacturer’s instructions and the applicable requirements for inspection, cleaning, and maintenance. The condition of the gear and the nature of its contamination may also affect the service selected.
2. CO₂ is maintained in liquid form
The machine controls pressure and temperature to keep carbon dioxide in the state required by its cleaning process.
That controlled environment allows the equipment to use liquid CO₂ as its cleaning medium. The machine is specifically engineered to operate under those conditions; this is not a process that can be replicated with ordinary carbon dioxide containers or improvised equipment.
3. The cleaning medium contacts the gear
The system circulates or otherwise moves liquid CO₂ through the treatment chamber, bringing it into contact with the materials being cleaned.
Cool Clean describes the low viscosity and surface tension of liquid CO₂ as properties that help its systems move through complex spaces and between layers of material. The degree to which a particular process reaches contaminants within a garment depends on the equipment design, operating conditions, garment construction, and treatment method.
That distinction matters for firefighter PPE. Protective ensembles contain multiple layers with different functions, and the presence of a cleaning medium around a garment does not, by itself, prove that every contaminant has been removed.
4. The process removes targeted contamination
During treatment, the cleaning process is designed to separate targeted contaminants from the material and carry them away.
The outcome depends on the substances involved and the process used. Results for one contaminant cannot automatically be applied to another, and performance data from one system should not be treated as proof of the performance of every liquid CO₂ machine.
This is why departments should look for testing that identifies the contaminants evaluated, the equipment and process used, and the measured results.
5. The CO₂ is recovered or released according to the system design
Many industrial liquid CO₂ cleaning systems use a closed-loop design that recovers and reuses the carbon dioxide. At the end of a treatment cycle, the machine manages the CO₂ according to its engineered process.
Cool Clean describes its liquid CO₂ cleaning technology as a closed-loop process that recaptures and reuses CO₂. Exact operating and recovery arrangements depend on the equipment.
The treated gear must still be handled, inspected, and returned to service in accordance with applicable procedures. A completed cleaning cycle does not replace any required inspection, maintenance, or other PPE-care steps.
Why use liquid CO₂ for firefighter gear?
The potential value of liquid CO₂ decontamination comes from the properties of the cleaning medium and the capabilities of the specific system.
An alternative to water-based cleaning
Liquid CO₂ systems use a different cleaning medium from traditional water-based extractors. That gives departments another option to evaluate when considering how to address contamination on protective equipment.
The distinction is especially relevant when a department wants to understand how different processes perform against particular substances. The right comparison depends on actual test results, not simply whether a process uses water or CO₂.
Potential to address contaminants within layered garments
Firefighter turnout gear is designed with multiple layers that serve different protective functions. Contaminants may remain on surfaces or within materials after an incident.
Liquid CO₂ system manufacturers describe the properties of the medium as helping it move between layers of protective clothing. However, departments should look for evidence demonstrating performance on relevant materials and contaminants rather than assume that a process reaches or removes everything within a garment.
Different equipment and service configurations
Liquid CO₂ technology is not a single, universal process. Systems can differ in design, operating method, and intended application.
For example, Cool Clean offers multiple CO₂ system configurations, including systems with different water-use requirements. The appropriate configuration and service process must be evaluated against the applicable PPE-care requirements.
What does the testing show?
One of the most important questions for any department considering advanced decontamination is whether the process has demonstrated the performance being claimed.
Emergency Technical Decon (ETD) publishes results from testing of its Liquid CO₂+ process. Its reported findings include removal of 84% of tested per- and polyfluoroalkyl substances (PFAS), 99.9% of tested semivolatile organic compounds (SVOCs), 99.8% of tested heavy metals, and 99.9999% of tested biological contaminants.
These are provider-specific results for the contaminants and process tested. They should not be generalized to every liquid CO₂ system, every contaminant, or every set of operating conditions. Review ETD’s published testing and study results.
For department leaders, the useful questions go beyond a single percentage:
- Which specific substances were tested?
- What gear materials and treatment conditions were used?
- How were the results measured?
- Who conducted or verified the testing?
- What limitations did the testing identify?
- Does the evidence apply to the service being proposed for your department?
A credible evaluation connects the performance claim to the actual test. It also recognizes that removing a contaminant from gear is not the same as proving a reduction in an individual’s long-term disease risk.
Does liquid CO₂ replace traditional turnout gear washing?
Not automatically. Routine cleaning remains an essential part of firefighter PPE care, and departments must continue to follow applicable standards and manufacturer instructions.
The National Fire Protection Association’s (NFPA) 2025 edition of NFPA 1850 addresses the selection, care, and maintenance of protective ensembles for structural and proximity firefighting and self-contained breathing apparatus. It consolidates the previous NFPA 1851 and NFPA 1852 standards. The 2025 edition also addresses cleaning verification and specialized cleaning processes.
Departments should evaluate a particular liquid CO₂ system and service process against the requirements that apply to their equipment. A technology label alone does not establish compliance.
To understand how these approaches compare in practice, read Article 4: Traditional Washing vs. Liquid CO₂ Decontamination for Firefighter Gear.
How can departments evaluate a liquid CO₂ provider?
Before selecting a provider, fire chiefs and PPE officers should evaluate both technical qualifications and practical service delivery.
Consider these questions:
- Equipment certification: Does the provider use equipment that meets the program’s required certification and qualification criteria?
- Process evidence: Can the provider document the process used and supply relevant performance testing?
- PPE compatibility: Is the service appropriate for the specific gear and its manufacturer instructions?
- Inspection and maintenance: Can the provider support required inspections and identify equipment that needs further attention?
- Logistics: What are the costs, transportation requirements, turnaround times, and reporting arrangements?
- Standards: Can the provider explain how its process fits within applicable PPE-care requirements?
Afterburn’s provider qualification model is based on equipment certification and performance, not simply on a brand name. Departments should confirm that the specific equipment and service meet the program’s current requirements.
What if advanced decontamination is outside your budget?
A department can understand the potential value of an additional cleaning option and still struggle to pay for it.
That is particularly relevant for departments managing limited operating budgets, long transportation distances, or competing equipment and staffing needs. The challenge is not necessarily a lack of interest in gear care. It may be a lack of access to a service that fits the department’s financial and operational circumstances.
The Afterburn Foundation helps qualifying fire departments access advanced PPE decontamination when cost stands in the way. Afterburn raises philanthropic funding and connects qualifying departments with qualified independent service providers. It does not manufacture equipment or operate a cleaning facility.
Its annual sponsorship model is straightforward:
$500. One firefighter. One year.
A $500 sponsorship provides one firefighter with one year of funded access to qualifying advanced PPE decontamination services. The standard annual service model is designed around two advanced CO₂ decontamination cycles and one annual advanced inspection, with flexibility to fund services according to actual need.
Funding is pooled, allowing services and costs to vary according to equipment, exposure, geography, and logistics. The sponsorship is a commitment to annual access, not a guarantee that every firefighter will receive an identical package of services.
Frequently asked questions
What is liquid CO₂ decontamination?
It is a specialized cleaning process that uses carbon dioxide maintained in liquid form under pressure to treat contaminated equipment. The specific process and its performance depend on the system and contaminants involved.
How does liquid CO₂ remove contaminants from firefighter gear?
The system brings liquid CO₂ into contact with the gear to help separate targeted contaminants from the material and carry them away. The results depend on the equipment, treatment process, contaminant, and supporting evidence.
Is liquid CO₂ decontamination better than water washing?
Neither method should be declared universally superior without specifying the contaminant, equipment, and process being evaluated. Routine washing remains essential, while advanced CO₂ decontamination provides another option for departments to assess using relevant performance testing.
Does liquid CO₂ decontamination prevent firefighter cancer?
No. A cleaning process should not be represented as preventing cancer. Testing may demonstrate reductions in particular contaminants, but that does not establish that the process prevents cancer or eliminates occupational exposure risks.
Can a fire department receive funding for liquid CO₂ decontamination?
The Afterburn Foundation helps qualifying departments access advanced PPE decontamination when cost is a barrier. Departments can apply for funding to have their needs evaluated.
Better decontamination shouldn’t depend on your department’s budget.
Afterburn helps qualifying fire departments access advanced PPE decontamination when cost stands in the way.
Help another department get access: Sponsor a Firefighter
Traditional Washing vs. Liquid CO₂ Decontamination for Firefighter Gear
Fire departments already know that contaminated turnout gear needs proper care. The harder question is whether their existing cleaning procedures are enough for the exposures their firefighters encounter, or whether additional decontamination options deserve consideration.
Traditional washing remains a fundamental part of firefighter personal protective equipment (PPE) care. Liquid carbon dioxide (CO₂) decontamination offers another approach, using specialized equipment and a different cleaning medium.
These methods are not interchangeable in every situation, and neither should be judged by a blanket claim that it works or does not work. The useful comparison is more specific: What does each process do? What evidence supports its performance? And which approach fits the department’s equipment, needs, and resources?
Traditional washing and liquid CO₂ decontamination: the short answer
Traditional washing uses an appropriate laundering process to remove soil and contamination from protective equipment. Liquid CO₂ decontamination uses pressurized liquid carbon dioxide as a specialized cleaning medium intended to reduce targeted contaminants.
Both approaches have a place in the broader conversation about firefighter gear care. Routine washing remains essential. Advanced CO₂ decontamination provides an additional option that departments can evaluate based on the contaminants involved, the specific system, supporting test results, and applicable PPE-care requirements.
The important distinction is not that one method is universally good and the other is universally bad. It is that different processes may produce different results against different contaminants.
How traditional turnout gear washing works
Traditional washing uses a controlled laundering process to remove contamination from protective garments.
Departments commonly use dedicated turnout gear extractors or other equipment designed for protective clothing. The process may involve water, appropriate cleaning agents, mechanical action, and a specified cycle.
What washing can accomplish
Proper washing can remove visible soil and reduce contamination on firefighter gear. Its performance depends on the garment, the contaminant, the cleaning equipment, and the procedures used.
A well-managed washing program also supports the broader maintenance of PPE. It gives departments a repeatable way to care for equipment, document service, and prepare garments for any required inspection or return-to-service decisions.
These are important functions. Advanced decontamination does not make them unnecessary.
Where washing requires careful evaluation
Not all contaminants respond to cleaning in the same way. Some substances may be difficult to remove fully from particular materials using a given washing process.
That does not mean water-based washing is ineffective. It means departments should understand the limits of their specific procedures and avoid assuming that a garment’s appearance proves every contaminant has been removed.
When evaluating performance, the relevant questions concern the contaminants tested, the equipment used, the treatment conditions, and the results measured.
How liquid CO₂ decontamination works
Liquid CO₂ decontamination uses carbon dioxide maintained in liquid form under pressure. Specialized equipment brings the cleaning medium into contact with protective materials to help remove targeted contaminants.
The process differs from conventional water-based laundering in its cleaning medium and operating conditions.
What makes the process different?
Liquid CO₂ has physical properties that make it useful in specialized cleaning systems. Manufacturers describe its low viscosity and surface tension as properties that can help the medium move through complex spaces and between layers of material.
However, the fact that a cleaning medium can contact a material does not prove that every contaminant has been removed. Results depend on the machine, process, garment construction, and substance being evaluated.
What does the testing show?
Emergency Technical Decon (ETD) publishes results from testing of its Liquid CO₂+ process. Its reported results include 84% removal of tested per- and polyfluoroalkyl substances (PFAS), 99.9% of tested semivolatile organic compounds (SVOCs), 99.8% of heavy metals, and 99.9999% of tested biological contaminants.
Those figures are specific to the tested process and contaminants. They should not be generalized to every CO₂ system or treated as proof of performance against all possible contaminants.
For departments, the value of these results is that they provide specific performance claims to examine. A sound evaluation should identify what was tested, how results were measured, and whether the evidence applies to the service being considered.
Comparing the two approaches
| Consideration | Traditional washing | Liquid CO₂ decontamination |
|---|---|---|
| Cleaning medium | Typically water and appropriate cleaning agents | Pressurized liquid carbon dioxide |
| Primary role | Routine removal of soil and contamination | Additional treatment option for targeted contaminants |
| Equipment | Suitable turnout gear extractors or other approved laundering equipment | Specialized liquid CO₂ cleaning system |
| Performance | Depends on garment, contaminant, and washing process | Depends on system, process, contaminant, and supporting evidence |
| Place in PPE care | Essential component of routine care | Evaluated as an additional option |
| Department considerations | Procedures, equipment, detergent, maintenance, and records | Certification, performance evidence, PPE compatibility, provider qualifications, and logistics |
The table describes general differences between the approaches. It is not a performance ranking, and it does not establish that either process will deliver the same results across every garment or contaminant.
Which contaminants are we talking about?
The answer matters because firefighter gear can encounter many different substances, and the effectiveness of a cleaning process depends on what it is being asked to remove.
Combustion-related contaminants
Structural fires can expose protective equipment to soot, particulates, and chemicals produced by burning materials. Wildland fires, vehicle fires, and other emergency responses can create different exposure mixtures.
The presence and concentration of contaminants vary by incident. Departments should not assume every garment carries the same substances or requires identical treatment.
PFAS in protective equipment
Per- and polyfluoroalkyl substances, commonly called PFAS, are a large group of chemicals used in many industrial and consumer applications. Research from the National Institute of Standards and Technology (NIST) has identified PFAS in structural turnout gear textiles, gloves, hoods, and wildland firefighting textiles.
The findings raise important questions about exposure from protective equipment. However, the health risks attributable specifically to PFAS in firefighter gear remain under investigation.
When comparing cleaning methods for PFAS, departments should look for test results tied to the actual process and materials. A result for one tested substance or system does not establish equivalent performance against all PFAS or other contaminants.
Other substances
Firefighter PPE may also encounter metals, semivolatile organic compounds, and biological contaminants, depending on the incident.
Testing for one category should not be treated as evidence that a process addresses every other category. Departments should examine which substances were tested and what the results actually demonstrate.
How should a department compare cleaning performance?
A useful comparison begins with evidence rather than broad claims about technology.
Look for testing that identifies the process
Ask providers to identify the specific equipment and process used in their testing. Results from one liquid CO₂ system cannot automatically be applied to another. The same principle applies to washing equipment and different laundering procedures.
Examine the contaminants tested
A report should identify the substances evaluated and explain the conditions under which they were tested.
A high removal percentage for one substance does not establish the same result for another. Departments should also distinguish between a measured reduction and complete removal.
Consider the equipment and test conditions
Protective garments have different materials, layers, and construction. Results obtained under one set of conditions may not translate directly to every garment or service configuration.
Ask whether the evidence applies to the PPE your department uses and whether the proposed treatment is compatible with manufacturer instructions and applicable requirements.
Keep performance claims separate from health outcomes
A test demonstrating reduced contamination on gear is not proof that a cleaning process prevents cancer.
Firefighter occupational cancer is a serious concern, and managing exposure is an important part of occupational health. But no single cleaning method should be presented as eliminating exposure or guaranteeing a health outcome.
The goal is to make decisions supported by evidence while continuing to address the many sources of occupational exposure firefighters encounter.
What do standards mean for this decision?
The National Fire Protection Association’s (NFPA) 2025 edition of NFPA 1850 consolidates the previous NFPA 1851 and NFPA 1852 standards, addressing the selection, care, and maintenance of covered protective ensembles and self-contained breathing apparatus.
Departments should review the current standard and their equipment manufacturers’ instructions when evaluating cleaning procedures and alternative technologies.
The relevant question is not whether a service uses a particular cleaning medium. It is whether the specific equipment and process are appropriate for the gear, meet applicable requirements, and have adequate supporting evidence.
A provider should be able to explain its process, identify relevant equipment qualifications, and document the services performed.
Cost, logistics, and access matter too
Even when a department identifies a promising cleaning option, practical constraints can determine whether it can use the service.
Consider:
- Service costs: What does the treatment cost for the equipment your department needs serviced?
- Transportation: Does the service require shipping or travel to a provider?
- Turnaround: How long will the gear be unavailable, and what arrangements are needed to maintain operational readiness?
- Inspection: What inspections or other maintenance steps are required before the gear returns to service?
- Documentation: Will the department receive records of the service and any relevant findings?
- Availability: Is a qualified provider accessible to your department’s location?
These considerations are particularly important for small, rural, volunteer, and combination departments. Geography can affect access just as much as a line item in the annual budget.
A technology is not a practical solution for a department if it cannot reasonably access the service or manage the associated logistics.
Where Afterburn fits
The Afterburn Foundation helps qualifying fire departments access advanced PPE decontamination when cost stands in the way.
Afterburn is an access and funding organization, not a manufacturer or cleaning facility. It connects documented department need with philanthropic funding and qualified independent service providers.
Its annual sponsorship model is built around the following commitment:
$500. One firefighter. One year.
A $500 sponsorship provides one firefighter with one year of funded access to qualifying advanced PPE decontamination services. The standard annual model is designed around two advanced CO₂ decontamination cycles and one annual advanced inspection, while allowing the funded services to vary according to actual need.
Sponsorship funds are pooled so that differences in equipment, exposure, geography, and logistics can be accommodated. The model funds annual access rather than promising that every firefighter will receive the same set of services.
For departments that already have routine washing in place but face a financial barrier to advanced decontamination, Afterburn offers a way to explore potential assistance.
If your department is considering advanced decontamination but cannot afford the service, you can apply for funding.
Frequently asked questions
Is traditional washing effective for firefighter turnout gear?
Yes. Properly performed washing is an essential part of PPE care and can remove soil and reduce contamination. Results depend on the contaminants, equipment, and cleaning procedures used. Some substances may be difficult to remove fully through a particular process.
Is liquid CO₂ decontamination better than traditional washing?
There is no universal answer. Performance depends on the contaminant, garment, equipment, and process. Departments should compare relevant test results and applicable requirements rather than assume one approach is superior in every situation.
Can liquid CO₂ decontamination replace a gear extractor?
Departments should not assume that advanced CO₂ decontamination eliminates the need for routine cleaning equipment or established PPE-care procedures. They should evaluate how the specific service fits into their overall program and applicable requirements.
Does liquid CO₂ decontamination remove PFAS?
Testing published by Emergency Technical Decon reports removal of 84% of tested PFAS using its Liquid CO₂+ process. That result applies to the substances and process tested. It should not be generalized to every PFAS compound or every CO₂ cleaning system.
Can Afterburn help pay for advanced decontamination?
Yes. Afterburn helps qualifying fire departments access advanced PPE decontamination when cost stands in the way. Departments can apply for funding and have their needs evaluated.
Better decontamination shouldn’t depend on your department’s budget.
Afterburn helps qualifying fire departments access advanced PPE decontamination when cost stands in the way.
Help another department get access: Sponsor a Firefighter