Ever stood by a smoky fence line, garden hose in hand, and wondered how the pros seem to knock down fire so quickly? Or maybe you’ve been on a brigade crew, lining up the tankers and prepping to attack a stubborn grass fire, and heard someone call out for “Class A” or “Class B” foam. For most Australians—whether you’re looking after family, your pets, or your property, or you’re donning the yellow gear for a shift—knowing when and how to use firefighting foams can be a game changer.

But here’s the thing: using foam safely and effectively isn’t just for fireys. Understanding the basics can help you make better choices at home, on your property, or even in your workplace. This guide covers everything you need to know about Class A and B foams—what they are, when to use them, and, most importantly, how to use them without risking your health or the environment. Whether you’re a first-timer, a community leader, or on the frontline, you’ll find calm, practical advice right here.

Plus, if you want to take your fire preparedness kit to the next level, explore these top-rated safety and go bags—handy for both families and crews heading out to a job. Let’s break down foams, bust some myths, and help you act with confidence when it counts.

In plain terms, firefighting foams are liquids you add to water to help it put out fires faster, safer, and with less effort. “Class A foam” is made for ordinary fires—think grass, bush, timber, paper, or your backyard shed. “Class B foam” is designed for flammable liquids—like petrol, diesel, oils, or paints. Getting the difference right matters. The wrong foam won’t do the job and, worse, might put people or the environment at risk.

For most people outside the fire service, foam seems high-tech or risky. But it’s just another tool—one that, when used with care, can mean the difference between a minor flare-up and a dangerous emergency.

Class A Foam—Your Bushfire and House Fire All-Rounder

This foam is used for “ordinary combustibles”—grass, timber, leaves, hay, mulch, paper, even the back wall of your shed. Class A foam breaks down the surface tension of water, letting it soak deep into burning material, so fires go out faster and are less likely to flare up again.

Most Class A foam is biodegradable, non-toxic in normal concentrations, and easy to rinse away—making it safe for use around homes and stock (as long as you follow local advice). Fire crews love it because it stretches the water supply, covers more ground, and leaves a visible wet line that helps prevent rekindling.

• Ideal for: Bushfires, grassfires, structure fires, rubbish fires
• Common mistake: Using too much foam—wastes product and may create slippery surfaces
• Household tip: If a crew uses foam on your property, wait until they say it’s safe before re-entering the area

Class B Foam—For When Things Get Risky With Liquids

Class B foam is for flammable liquid fires—think petrol stations, fuel spills, car accidents with leaking tanks, chemical storage, and paint shops. This foam forms a “blanket” over the liquid, starving the fire of oxygen and stopping dangerous vapours from escaping. Using the wrong foam on these fires can be catastrophic, and the environmental risks are serious.

Modern Class B foams are strictly regulated—many older types are now banned due to contamination concerns. Only properly trained crews should handle them. If you’re near a liquid fire incident, stay well clear and follow emergency services’ advice.

• Ideal for: Fuel tanker crashes, chemical plant fires, industrial spills
• Common mistake: Trying to tackle a liquid fire with water or the wrong foam—don’t risk it
• Public tip: If you store fuel, oils, or chemicals at home or work, check your local fire plan and storage rules

For Crews and Firefighters

1. Check your foam stock: Confirm the expiry, type, and mix ratio. Older Class B foams may require specialist disposal.
2. Set your foam proportioner: Use the correct setting—typically 0.1% to 1% for Class A, 3–6% for Class B. Double-check before pumping.
3. Test and observe: Run a quick test line to confirm the mix is correct. Check for even coverage and watch for signs of over-foaming.
4. Communicate clearly: Let your crew know which foam is in use, and watch for cross-contamination (especially with Class B foams).
5. Apply safely: Use smooth, sweeping motions for Class A foam on vegetation. For Class B, approach from upwind, lay a foam “blanket,” and never break the surface tension.
6. Decontaminate gear: After the job, rinse hoses, nozzles, and PPE—especially after Class B foam. Log usage for environmental records.

For Households, Businesses, and Community Leaders

• Know your risk: If you live near industrial sites, transport corridors, or have bulk fuel storage, ask your local brigade about foam use and any public health considerations.
• Keep clear of foam lines: Don’t enter areas where foam has just been applied—wait for advice, especially after a fuel or chemical fire.
• Pet and garden safety: Most Class A foams are pet-safe after drying, but always check with the crew on scene. Wash down produce before eating if foam has landed on your vegie patch.
• Report concerns: If you notice unusual smells, residue, or environmental impacts after a fire, let your local council or fire authority know.

• Using foam on the wrong fire: Applying Class A foam to a fuel spill, or Class B foam to a house fire, is not just a waste—it’s dangerous. Double-check labels and MSDS sheets every time.
• Over-foaming: More isn’t always better. Too much foam can reduce visibility, waste water, and create clean-up headaches. Use just enough for a thin, effective coat.
• Forgetting environmental impact: Foam run-off, especially from Class B, can harm waterways or soil. Always block drains and use minimal product near gardens or dams.
• Neglecting PPE and clean-up: Even “safe” foams should be handled with gloves and goggles, and all gear washed thoroughly after the job.
• Household myth: “A bit of detergent is the same as foam.” Not true—proper foams are engineered for fire safety, not just bubbles.

• Foam for overhaul: After the flames are out, Class A foam can help soak hot spots and hidden embers, especially in deep mulch or timber piles. I’ve seen more than one “out” fire restart hours later because a crew skipped the foam finish.
• Mixing matters: Not all foams play nicely with every pump, hose, or nozzle. Test on a small patch before you start, especially with older gear or unfamiliar brands.
• For renters and residents: If you return to a home after foam use, check for any residue or slippery spots, especially in sheds or driveways. Rinse before you walk pets or kids through the area.
• For businesses: If you store fuels or chemicals, get clear instructions from your local fire service about foam use and environmental safety. Prevention is always cheaper than clean-up.
• For crews: If you’re first on scene to a car or truck fire, remember: Class B foam only if you’re sure of a liquid fuel involvement—don’t waste precious foam if water or Class A will do.

The good news? With a little know-how and teamwork, foams make firefighting safer for everyone. You don’t have to be a scientist—just pay attention to details, learn from others, and don’t rush the basics.

Firefighting foam has come a long way. Decades ago, Class B foams (especially those containing PFAS) caused long-term contamination in some communities. Today, stricter rules mean only safer products are used, and Class A foams are generally low-risk if used sensibly.

Still, always follow local advice on clean-up and disposal. Never hose foam run-off into drains, creeks, or waterways. If you see foam being used, keep pets and livestock away until the area’s been cleared. If you’re a business, work with your fire warden and local authority to develop a clean-up plan in advance.

• Rural properties: Block off dams or tanks if foam is being used nearby
• Urban homes: Rinse paths and hard surfaces, but avoid pushing foam into gutters
• Crews: Log foam use for environmental reporting—new rules require this in many areas
• Everyone: If you have questions, find more environmental advice from the Department of Health

If you’re preparing a fire plan—at home, in your business, or with your brigade—add “foam awareness” to your checklist. Know what products are stored nearby, how crews might use foam, and what steps to take after a fire. Not every home or shed will need foam, but knowing what to expect removes fear and confusion when every minute counts.

• For home and renters: Include “foam clean-up” in your after-fire checklist
• For businesses: Train staff in safe storage, spill management, and how to stay clear of foam operations
• For crews: Add foam drills and maintenance checks to regular training
• For community groups: Host info sessions to explain foam basics and environmental care

Preparation is key. When you know what to expect, you’re less likely to make rushed decisions or put yourself in harm’s way.

Want to go deeper? See our other essential guides for families, businesses, and crews:

• Campfire Safety Tips: Setup, Shutdown, and Peace of Mind
• Preparing for Fire Season and Grass Fires in Australia
• Understanding Bushfire Attack Levels (BAL): A Comprehensive Guide

Ready to step up your fire safety game? Take five minutes today to chat with your family, crew, or colleagues about foam use and clean-up. The more you know, the safer you’ll be—on the fireground, at work, and at home.

This article was created using practical emergency preparedness and firefighting advice and reviewed for clarity. It is intended as general public information for Australian households, communities, and emergency service teams.