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. 

Transcript

Introduction to Ignition Sources

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

Four Categories of Ignition Sources

Speaker 1 1:51

, 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

Controlling Flammable Liquid Risks

Speaker 1 4:01

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 .