What are aqueous film-forming foams (AFFFs)?

When many modern safety guidelines were originally instituted, little was known about PFAS, including their ability to linger in the waste stream and within our own bodies.

“There was never really a reason to contain AFFF, because everyone thought it was similar to soap,” said Jill Greene, CDM Smith principal and an expert in hazardous waste and hydro­ge­o­logic inves­ti­ga­tions. With little to no evidence of their hazardous potential, AFFF became ubiquitous. Today, they are a common cause of PFAS cont­a­m­i­na­tion throughout the world.

There was never really a reason to contain AFFF, because everyone thought it was similar to soap.

Jill Greene, CDM Smith, Principal

While the Federal Aviation Admin­is­tra­tion (FAA) and Department of Defense (DoD) have started inves­ti­gat­ing alternative foams that do not contain PFAS, an efficient protocol for replacement has not yet been found. “The problem is decon­t­a­m­i­na­tion and system compat­i­bil­ity,” Greene said. There is currently no standard practice for effectively removing PFAS compounds from pumps, tanks, trucks and hangar fire suppression systems. Individual components, if not the entire foam delivery system, may need to be replaced to be compatible with the new product. Furthermore, the latest health advisories for PFAS call for extremely low levels, measured in the parts-per-trillion. That means an increased likelihood of aggressive remediation of PFAS from discharges of AFFF to the environment, down to an almost non-detectable level.

The dual nature of AFFF as life-saving fire­fight­ing foam and hazardous PFAS conduit is at the heart of current research to find alter­na­tives that will save lives with the same efficacy and also protect the environment. FAA has taken early steps to stem the discharge of PFAS via AFFF trans­mis­sion by providing guidance on testing foam dispensing equipment without discharging foam to the environment. But fire­fight­ers can’t train for large-scale disasters if they can’t actually spray the foam. And in the event of a real emergency, researchers are struggling with how to treat first responders and victims who come into contact with the foam. “How do you decon­t­a­m­i­nate people and equipment that have come in contact with AFFF?” said Greene. “No one has really had to do this before.” So far, water utilities have received the majority of the spotlight when it comes to PFAS coverage in the news. But many experts believe that airports are next. While researchers continue to study the behaviors of PFAS in the environment and search for new treatment solutions, here are best management practices that airports can take now to lower the risk of cont­a­m­i­na­tion:

Products: According to Greene, many airport workers may have never had a reason to step inside Aircraft Rescue and Fire Fighting stations or hangars. For planning purposes, she says it is important for team members to take a physical tour of the facilities and record all products that can potentially pollute the environment upon release. Develop a foam inventory and stock tracking system documenting the foam composition, brand, and manu­fac­turer. “The first step of a prevention plan is knowing what you need to prevent,” Greene says. “Document what you have and get rid of anything expired or obsolete."

Use: Eliminate the use of AFFF products and other fluorinated “Class B foams for training and testing of foam systems and equipment” whenever possible. Provide containment, treatment, and proper disposal of foam solution. Avoid direct release to the environment to the greatest possible extent.

Fire suppression systems: Inspect and maintain fire suppression systems and evaluate the possi­bil­i­ties for accidental activation. When it comes to emergency prepared­ness, more is better. Greene recommends redundant activation measures like adding a flame detection camera in addition to existing heat sensors. Consider a subsurface storage containment system to help control the spread of dangerous pollutants in the event of an actual fire. “If the foam is dispersed, there would be a diversion valve to guide the material into the floor drains and to a contained unit underground,” said Greene.

Emergency response plans: In addition to incor­po­rat­ing extra safeguards into a suppressant system, it is also critical that airports design a compre­hen­sive response plan. In the unfortunate event of a real emergency, airport management will need to assemble a crisis support team, which can include fire­fight­ers and emergency personnel, airport Operations staff, envi­ron­men­tal staff, legal experts and and public relations profes­sion­als.