Ep. 24: Ignition Sources: What You Don’t See Could Start a Fire

What’s the most overlooked fire risk when working with Class 3 Flammable Liquids? The answer is ignition sources — and they’re not always obvious. 

In this episode, Patrick breaks down: 

• What ignition sources really are (it’s more than open flames) 
• Where they’re hiding in your workplace 
• The four main types: thermal, electrical, mechanical, and chemical 
• How to control risk using distance, signage, and training 
• What AS 1940 says about ignition sources and cabinet safety 

Ignition sources can be silent, invisible — and devastating. Don’t wait until it’s too late. Listen now and learn how to spot and stop the spark before it starts. 

Listen now wherever you listen to podcasts.  

🎧 Subscribe and share to help keep Aussie workplaces safe and compliant. 

Chapters

• 0:00 Introduction to Ignition Sources
• 1:51 Four Categories of Ignition Sources
• 4:01 Controlling Flammable Liquid Risks
• 5:14 Key Takeaways and Episode Closing

Transcript

Speaker 1: 0:06

Welcome to Chemical Safety at Work, the podcast that helps you navigate dangerous goods risks and keep your workplace safe, compliant and informed. I'm your host, Patrick G, and today we're tackling a really important aspect of managing class 3 flammable liquids ignition sources. Now most of us know that flammable liquids ignition sources. Now most of us know that flammable liquids need to be kept away from flames and sparks. But in a busy workplace, ignition sources aren't always easy to spot or control and if you're not paying close attention, they can quickly lead to fire, explosion and serious harm. So in this episode I'm going to walk you through what ignition sources are, where they might be hiding in your workplace and what you can do to eliminate the risk. Let's start with the basics. An ignition source is any object or condition that can produce enough heat to ignite flammable vapors, and when those vapors come within three meters of a source, that's all it takes to trigger a fire. It could be something obvious, like a welding torch, or something easy to miss, like a static spark from clothing or heat from a hot surface. Even a tiny ember can reach over 100 degrees Celsius more than enough to ignite a flammable substance. That's why identifying and eliminating ignition sources is one of the most important parts of working with flammable liquids. Ignition sources usually fall into one of four categories Thermal, electrical, mechanical and chemical. Now let's break each one down.

Speaker 1: 1:39

Thermal ignition sources are anything that gives off heat. We're talking about flames and blow torches, cigarette butts and lighters, hot surfaces like stoves, pilot lights and electric lamps, even glowing embers or welding sparks. These are the most visible types of ignition sources and some of the easiest to spot. Electrical ignition sources can be a bit trickier. They include electric motors and switches, broken cables or short circuits, sparks from static electricity, lightning strikes or stray currents. Even the flow of liquid or powder through pipes can build up static. In many cases you won't see a visible spark, but the risk is still there. Mechanical ignition sources come from equipment and movement. Think about friction from an abrasive wheel, bearings, overheating, jamming or material fractures, pistons or moving parts generating heat. These risks are common in workshops or industrial areas where mechanical processes are part of everyday operations, or industrial areas where mechanical processes are part of everyday operations. Chemical ignition sources involve exothermic reactions, which is when chemicals react and give off heat. Some examples are vigorous oxidizing reactions, exothermic polymerization, exposure of reactive substances like sodium metal to air. These reactions can ignite flammable vapours even without a spark.

Speaker 1: 3:08

So how do we control these risks? The key is distance and awareness. According to the Australian standard AS1940, there must be no ignition sources within the cabinet storing flammable liquids within three metres of the cabinet, measured laterally and up to 1 metre vertically, above any openings, including cabinet doors. Once you've identified ignition sources near your flammable storage areas, eliminate them and make it clear to everyone on site that those areas are high risk. That's where signage comes in. Your flammable liquids cabinet must be marked with no smoking, no ignition sources within three meters, in lettering at least 50 millimeters high, and the sign needs to be clearly visible even when the cabinet is closed.

Speaker 1: 3:59

Even the best signage won't help if your team doesn't understand the risks. That's why training is crucial. Make sure your staff, supervisors and contractors know what ignition sources look like, how to eliminate them and how to handle and store flammable liquids safely. If someone doesn't know what a risk looks like, they won't be able to protect themselves or anyone else. So here's what I want you to take away from today's episode.

Speaker 1: 4:30

Ignition sources are everywhere. They're not always obvious and if your workplace handles class 3 flammable liquids, identifying and eliminating those sources is non-negotiable. Remember, check the Australian standards, read your safety data sheets, train your team and never store flammable liquids within three meters of any ignition source. Thanks for joining me on Chemical Safety at Work. If you found this week's episode helpful, please subscribe to Chemical Safety at Work on your favorite podcast platform and rate or leave us a review. We love to hear from our listeners, so send us a message and let us know if there are any topics you'd like us to do a deep dive on. Until next time, stay safe, stay compliant and keep those flammable liquids under control.