Types of Firefighting Foam Used on Ships as per SOLAS: A Seafarer’s Guide

Firefighting is no joke on board a ship. When you’re miles away from land, surrounded by water but dealing with a raging fire, the right firefighting tools are literally lifesavers. One such tool? Firefighting foam. Let’s dive into the different types of foam used on ships in compliance with SOLAS (Safety of Life at Sea) regulations—and more importantly, what every seafarer should know about them.

Why Foam? Isn’t Water Enough?

Good question! Yes, water is all around us—but it’s not always the best option for tackling fires at sea. For example, when dealing with Class B fires — think fuel oil, diesel, or lube oil — using water can be dangerous and ineffective. This is where firefighting foam comes into play.

Foam blankets the fire, cuts off the oxygen supply, and cools the surface. It also forms a protective layer that prevents re-ignition. Now that’s what I call double protection!

SOLAS and Foam Firefighting Regulations

Before we get into the types of foam, it’s important to understand how SOLAS fits in. As per the International Maritime Organization (IMO), SOLAS sets minimum safety standards for ships, including fire safety.

So, the types of foam we use—and where and how we use them—are governed by these international rules. If you’re working onboard or preparing for exams like the COC, it’s essential knowledge.

Main Types of Foam Used on Ships

Let’s break down the most commonly used firefighting foams on ships as per SOLAS guidelines.

1. Protein Foam

This is the old-school type of foam, but still quite relevant depending on your vessel type.

• Composition: Made from hydrolyzed protein concentrate, stabilizers, and foam boosters.
• Foam Expansion: Low expansion (Ratio of 8:1 to 12:1).
• Application: Suitable for Class B fires—especially hydrocarbon-based fires (like fuel oil).
• Pros: Resistant to heat and lasts long after application.
• Cons: Breaks down in contact with water-soluble fuels and needs fresh water for mixing.

On my last tanker contract, we had to use protein-based foam for a drill. It’s thick and forms a good stable layer. But I remember our Chief Officer warning us—it can be a bit messy to clean up!

2. Fluoroprotein (FP) Foam

This is actually an upgraded version of protein foam with added fluoro chemicals.

• Composition: Protein foam base with fluorocarbon surfactants.
• Foam Expansion: Low expansion, similar to protein foam.
• Application: Also for Class B fires; ideal for hydrocarbon fuels.
• Advantages: Greater fluidity—”film-forming” property helps it spread quickly across the burning surface.
• Drawbacks: Still not very effective on polar solvents (like alcohol or ketones).

In simple terms—it flows better than regular protein foam, like pouring milk over cereal instead of cream.

3. Film-Forming Fluoroprotein (FFFP) Foam

Say that three times fast.

• What is it? It’s fluoroprotein foam with film-forming agents—making it even quicker at smothering fires.
• Why it works: Forms an aqueous film that seals the fuel surface, blocking oxygen contact almost instantly.
• Good for: Fuel tank fire, pump room, or engine room where hydrocarbon fires may start.

FFFP is used in both portable and fixed foam systems on many merchant vessels, especially oil tankers. It’s like the Swiss Army knife of firefighting foams—versatile and reliable.

4. Aqueous Film Forming Foam (AFFF)

If you’ve been on board any modern vessel recently, you’ve definitely heard of AFFF.

• Main Use: Found in both portable extinguishers and fixed foam systems.
• Best For: Class B fires, especially in engine rooms and helicopter decks.
• Properties: Fast-spreading, water-like foam with film-forming ability.
• Mix Ratio: Commonly 3% or 6% concentration.

AFFF is widely trusted because of its ability to quickly knock down flames and prevent re-ignition. I’ve personally seen a live demo where AFFF extinguished a simulated fuel spill in under 30 seconds. It’s impressive, trust me.

5. Alcohol-Resistant AFFF (AR-AFFF)

Sometimes, we transport more than just oil. What if you’re dealing with polar solvents like alcohols?

• Special Feature: Contains polymers that make the foam resistant to solvent-based fuels.
• Applications: Particularly useful when carrying polar cargo—like ethanol or methanol.

AR-AFFF keeps its integrity even when in contact with aggressive liquids that would normally break standard AFFF. It’s like adding a raincoat over the foam!

Expanding on Foam Expansion Ratios

You might have heard terms like low, medium, and high expansion foam. Let’s simplify those:

• Low Expansion: 1:1 to 20:1 — Dense and resistant to heat. Used on most tankers and bulk carriers.
• Medium Expansion: 20:1 to 200:1 — Good for enclosed spaces like engine rooms.
• High Expansion: >200:1 — Great for machinery spaces, but not suitable for open decks.

The higher the expansion, the more air within the foam. But note: higher expansion isn’t always better. It depends on the situation and area of fire. You wouldn’t use high-expansion foam on deck in windy conditions—it’d just blow away!

Where Are These Foams Used On Board?

Let me break it down by location:

• Engine Room: Typically uses AFFF or FFFP through fixed foam systems.
• Cargo Pump Rooms: Usually protected by AFFF or AR-AFFF in tankers.
• Flight Deck (on vessels like FPSOs or drill ships): AFFF sprays for quick Knockdown.
• Portable Foam Applicators: Often filled with AFFF for emergency use.

On one of my voyages on a crude oil tanker, we had an inspection drill where the foam system needed checking. It was a FFFP-based system protecting the cargo pump room. The foam wasn’t just for show—it had to meet SOLAS foam-to-deck area ratios.

Maintenance and Testing

No matter how good your foam is, regular testing is critical. SOLAS requires routine checks and maintenance. You can’t just store foam for ten years and expect it to work like day one!

• Shelf Life: Most foams have a shelf life of 10 years (check the manufacturer’s instructions).
• Foam Sampling: Annual sampling to test efficacy is a part of compliance checks.
• Endurance Testing: For fixed foam systems—check if discharge pumps are delivering the right pressure and rate.

Always log maintenance activities—it might save you from trouble during a port state control inspection.

Final Thoughts: Foam—Your Friend in Firefighting

As merchant navy officers and ratings, our first responsibility is the safety of ship, cargo, and crew. Understanding the different types of firefighting foam isn’t just theoretical—it’s practical know-how. Whether you’re on a tanker, bulk carrier, or container ship, always know:

• What type of foam is onboard
• Where the foam systems are located
• How to use them during an emergency

Next time your Chief Mate asks during a drill, “Which foam would you use here?”—you’ll be ready with more than just a guess.

Got your own sea story about firefighting drills or emergency situations? Drop it in the comments below—let’s learn from each other.

Stay safe and keep sailing smart, shipmates!

Further Reading and Official References:
– IMO Fire Safety Codes – Official Website
– SOLAS – IMO Official Convention Text