What you need to know about Foam fire extinguishers and the environment

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We have had a growing number of questions from customers who are concerned about fire-fighting foams that contain or may contain Perfluorooctanesulfonic acid (PFOS) or Perfluorooctanoic acid (PFOA). These fluorine chemicals are associated with C8 technology, are extremely stable and remain mobile in the environment for many decades.

In the article below, we try to clear the confusion by answering the questions that have been asked.

Do I really need foam fire extinguishers?

Foam is first and foremost an extinguishing agent for Class B (flammable liquid) fires in open containers and is not really needed in most of the premises it has been installed into. CO2 extinguishers, which are usually paired with foam extinguishers at fire points, have a Class B rating suitable for the limited amounts of Class B risk in a typical office or shop. Powder extinguishers have high Class B ratings and are more suited to spill or running liquid fires than foam, and such fires are more likely than large open top container fires.

The historical reason for the proliferation of foam dates back to when the main extinguishers were 9 litre water jet models. These had a 13A rating (covering 200 square metres of floorspace), were very heavy (14kg) and not safe on electrical equipment.  Often a lighter 4.5 or 6 litre water extinguisher was preferred but as they were only 8A rated (covering 100 square metres) users had to install double the number. The 5.5 litre Foam Spray extinguisher had the advantage of being lighter, yet with a 13A rating didn’t need installing in pairs, was safer near electrical equipment due to the spray nozzle and had the advantage of a Class B capability.

Modern water or water additive extinguishers with a spray nozzle in 3 or 6 litre size now have the same (or better) Class A ratings as foam, as well as the safety near electrical equipment and would actually suit many locations, so users should consider phasing these in when a foam extinguisher is due a 5-year extended service. Water mist extinguishers are also another option as these have Class F (cooking oil) ratings so are a potential alternative to PFAS containing wet chemical or ABF foams.

I have foam extinguishers – do I need to replace them?

If your extinguishers have been subject to regular servicing including refilling during Extended Service at 5 years (or replacement) then they are unlikely to contain PFOS or PFOA and so can remain in service pending future legal developments. Even if a ban is brought in, there is likely to be a lead in period allowing natural phase out of existing extinguishers as was the case with AFFF containing PFOA.

If the extinguisher is very old with no service record or no verifiable refill record then it should be assumed to be potentially containing PFOS or PFOA and environmentally disposed of.

The same dates and principles would apply to wet chemical/ABF foam extinguishers that have PFAS as part of the contents.

 Can I discharge foam extinguishers?

Other than in fire emergencies there should be no discharge of foam extinguishers and in fact this would be illegal for PFOS and PFOA extinguishers. Training use of foam should not occur unless the site holds an Environmental Permit and can capture foam run off for high temperature disposal.

Extinguishers being removed from service must not be discharged other than by a licensed disposal company who will capture the foam in containers for high temperature disposal.

Why was AFFF developed for use in fire extinguishers?

In the late 1960’s firefighting - particularly of flammable liquid fires - was revolutionised by the invention by 3M of ‘Light Water – the first Aqueous Film Forming Foam (AFFF). AFFF is comprised of a mixture of surfactants, principally fluorosurfactants, which create a foam that flows more quickly over flammable liquids, creating a thin smothering film and a superior performance to traditional foams which are derived from animal proteins.

Do other types of fire extinguisher contain AFFF?

Since the late 1970’s AFFF has been used in portable extinguishers as a high performing multipurpose agent for mixed Class A and Class B risk environments. It is one of the most common fire extinguishers in use in the UK.

Whilst wet chemical extinguishers, primarily for Class F fires, are mostly based around Potassium Salts, some have AFFF added to give a better Class B rating and others (modelled as ABF or Class F foams) are AFFF extinguishers with an additive to make the foam blanket more resistant to the heat of a Class F fire, so some of these extinguishers are affected by this issue

Water additive extinguishers generally use metallic salts as an additive so are not affected and although some early versions from the 1980’s and 1990’s did use a small amount of AFFF as the additive, these will have long disappeared from service.

What are the associated environmental problems?

In recent decades the fluorosurfactants have been found to have a risk to the environment and human health, being a persistent organic pollutant (one of the so called "forever chemicals") found to accumulate in the general environment and in the tissues of humans with deleterious effects to both.

As a result of this discovery both voluntary and legally binding restrictions have been introduced in recent years and more are planned in coming years.

Which chemicals are involved?

The family of substances used in AFFF that cause the pollution issues are the PFAS (per- and polyfluoroalkyl substances) chemicals. Over the years the formulation of AFFF has been changed to reduce the harm from the chemicals by using PFAS compounds with a shorter fluoro-carbon chain.  These are thought to be less persistent and harmful, but by no means completely environmentally safe.

PFOS (Perfluorooctane sulfonate – C8)

The original version of AFFF contained PFOS, a most harmful version of PFAS and was withdrawn from manufacture and use throughout the early 2000’s in North America and Europe as well as being prohibited by environmental legislation.

As a result, no extinguishers containing PFOS were manufactured later than 2011 and should no longer be in service. An extinguisher found that is older than this should be withdrawn for environmental disposal unless it is known beyond doubt it has been subject to regular servicing and had an extended service where a non PFOS AFFF has been used to refill within the last 5 years

PFOA (Perfluorooctanoic acid – C8)

The formulation of AFFF using PFOA is also a harmful C8 long chain PFAS. Notice of prohibition was issued in 2010 (with a 2022 enactment) with most manufacturers stopping the use of PFOA in the 2010-2012 period. As a result, extinguishers using PFOA should have been removed from service by 2022 unless it is known beyond doubt it has been subject to regular servicing and had an extended service where a non PFOA AFFF has been used to refill it.

PFHxA (Perfluorohexanoic acid – C6)

Foam extinguishers in current circulation should contain AFFF based on PFHxA, a shorter C6 chain PFAS with less (but not zero) environmental effect. Most extinguishers in circulation with ‘Eco’ or similar branding use this version of AFFF.

As it is still harmful to the environment a PFHxA phase out and ban is likely to be introduced in 2023/2024 meaning even these extinguishers will ultimately require removal from service

Fluorine Free Foams

A range of fluorine free foam compounds with no PFAS content have now been developed, including ones intended for portable extinguisher use, and these are slowly entering the market and are not likely to be subject to restrictions for the foreseeable future

 Do Firechief fire extinguishers contain PFOS or PFOA?

All film forming foams used in our extinguishers do not contain fluorosurfactants based on C8 technology and therefore do not contain PFOS or PFOA.

Firechief Global is committed to developing PFAS free firefighting technology, enabling the elimination of PFAS-based fire extinguishing compounds from the Firechief product range. We have a PFAS Free symbol on the product information to which this currently applies.

Fire Depot has been the UK's favourite fire safety supplier for over 50 years, we know the fire protection and prevention business inside out. Our experienced team can offer advice and guidance about any of our fire safety products. For expert help and advice, please contact the Fire Depot team on 0330 999 2233, email us at sales@firedepot.co.uk or visit https://www.firedepot.co.uk/ to see our full range of fire safety products.

The information contained within this blog is provided solely for general informational and educational purposes and is not intended as a substitute for professional advice. Before taking any actions based upon this information, we advise the reader to consult any and all relevant statutory or regulatory guidance and where felt necessary to consult a qualified fire or industry regulation professional. The use or reliance on any information contained herein is solely at the reader’s risk.