Switching from AFFF to fluorine-free foam? Don’t forget the PFAS residues

Many fire brigades, industrial sites, airports, and fire protection companies are currently facing the same question:

What do we do with old AFFF systems?

AFFF (Aqueous Film-Forming Foam), was widely used for flammable liquid fires because it worked fast and reliably. But many traditional AFFF products contained PFAS: highly persistent chemicals that can remain in water, equipment, tanks, and soil long after the foam itself has been used.

Today, many organizations are moving toward fluorine-free firefighting foams. That is an important step. But switching the foam is not always enough.

The hidden PFAS problem in old foam systems

When AFFF has been stored, pumped, sprayed, tested, or used in training, PFAS can remain in different places such as:

• foam tanks
• pipes and hoses
• fire suppression systems
• vehicles and equipment
• training grounds
• collection basins
• rinse water
• wastewater streams

Even after replacing the foam concentrate, residues can still be present inside the system. If these residues are not properly managed, they can contaminate new foam, cleaning water, or nearby soil and groundwater.

That means the transition to fluorine-free foam is not only a product switch. It is also a cleanup and cost-planning challenge.

What to do with affected rinse water?

One of the most overlooked issues during AFFF replacement is contaminated rinse water. To clean old foam systems, tanks and pipes often need to be flushed. If these systems previously contained PFAS-based AFFF, the rinse water will contain PFAS.

This water should not simply be discharged into drains, wastewater systems, or the environment. PFAS can pass through conventional treatment systems and continue spreading.

At the same time, disposing of or incinerating large volumes of PFAS-loaded water can become very expensive. This is where planning matters: instead of treating the full water volume as waste, PFAS can be selectively captured and concentrated in filter material. In the best case, the cleaned water can be handled at much lower cost, while only the PFAS-loaded filter material needs to be safely disposed of or destroyed.

For companies responsible for fire protection, this creates an important question: How can PFAS-contaminated water be captured, treated, and handled safely, without creating unnecessary disposal costs?

What companies should check before replacing AFFF

Before switching to fluorine-free foam, it helps to understand the current situation clearly.

Key questions include:

• Was PFAS-containing AFFF used in the past?
• Are old foam concentrates still stored on site?
• Which tanks, pipes, vehicles, or systems came into contact with AFFF?
• Where did foam runoff or training water go?
• Is there a plan for collecting and treating rinse water?
• Has the site been tested for PFAS contamination?

These questions are especially relevant for airports, industrial fire brigades, chemical sites, fire training facilities, military sites, and fire protection service providers.

We help with PFAS removal

At instrAction, we focus on selective PFAS removal from contaminated water streams. This can support companies dealing with AFFF residues, rinse water, and PFAS-impacted wastewater during the transition away from fluorinated firefighting foams.

Replacing AFFF is important. Planning what happens to the PFAS-loaded water is what makes the transition safe, responsible, and cost-efficient.

Need support with PFAS-contaminated rinse water or AFFF-related water streams?

Get in touch with our PFAS experts to discuss how selective PFAS removal can support your AFFF transition!