Ep. 12: Hidden Hazards of ‘Empty’ Chemical Containers and Gas Cylinders

In this episode of Chemical Safety at Work, hosts Mel and Pat dive into a counterintuitive but crucial topic—the dangers that linger in so-called “empty” chemical containers and gas cylinders. 

When chemicals are removed, is the risk gone too? Far from it. Mel and Pat uncover why these seemingly “empty” containers can still ignite fires, cause explosions, or release harmful vapours. 

They explore incidents where mishandling empty containers led to accidents and share practical steps for proper handling, storage, and disposal. 

Tune in to learn why “empty” containers require as much caution as full ones and discover how to keep your workplace safe and compliant with Australian Standards.

Free eBook:
https://offers.storemasta.com.au/controlling-risks-associated-with-hazardous-chemicals

Free chemical segregation chart: 
https://offers.storemasta.com.au/dangerous-goods-segregation-chart

Transcript

Mel: Hi everyone, and welcome to another episode of Chemical Safety at Work! I’m Mel— 

Pat: And I’m Pat. Today, we’re tackling a topic that might seem a little counterintuitive at first—safety issues with empty chemical containers and gas cylinders. 

Mel: That’s right. You’d think that once the chemicals are gone, the danger’s gone too, right? 

Pat: Not quite. Even when a chemical container or gas cylinder looks empty, it can still pose serious hazards—things like fire, explosion, toxic poisoning, and environmental contamination. 

Mel: And these risks aren’t just theoretical. There have been incidents where ‘empty’ containers have caused fires or even explosions. So today, we’re going to look at why these dangers exist, and what the regulations say about managing these so-called empty containers. 

Pat: We’ll also be sharing best practices for handling, storing, and disposing of these containers so that you can keep your workplace safe and compliant. 

Mel: Okay, let’s start by breaking down what the problem is. What makes an empty container or cylinder dangerous? 

Pat: Well, first off, they’re not actually empty. Even if the main contents have been removed, residues of the chemical—whether it’s liquid, gas, or solid—can still be present. And in some cases, those residues are just as hazardous as a full container. 

Mel: Exactly. If you think about flammable liquids, for example. When you’ve poured out a drum of, say, acetone, you’ll still have vapours left inside. These vapours can ignite just as easily as if the drum was full. 

Pat: The same goes for gas cylinders. Even when they’re ‘empty,’ there’s often still a small amount of gas left inside—enough to cause a fire or explosion if the conditions are right. 

In 2011 there was a fire and explosion in a Queensland junkyard when someone began cutting a supposedly ‘empty’ gas bottle with a cutting torch. Residual gas in the cylinder ignited leading to an explosion that caused injuries and extensive damage.  

Mel: That brings us to a key point: whether it’s a chemical container or a gas cylinder, they have to be treated as if they’re full until they’ve been properly decontaminated or gas-freed. 

Pat: And this isn’t just best practice—it’s a regulatory requirement. For example, under the Australian Standard AS 1940:2017 for flammable liquids, empty flammable containers have to keep their hazard labels until they’re completely decontaminated. And they need to be stored as if they’re still full, including keeping them away from ignition sources. 

Mel: The same rules apply for other dangerous goods classes, too. For example, toxic and corrosive substances have their own standards that outline how to handle and store these so-called empty containers safely. 

Pat: Yeah, with corrosives, even a tiny residue can damage skin, corrode metal, or even cause toxic vapours. So, empty containers need to be securely closed, stored properly, and clearly identified until they’re decontaminated. 

Mel: And decontamination can mean different things depending on the chemical. For some, it’s as simple as a thorough wash with water. For others, you might need to do a triple rinse with a specific solvent or use a neutralising agent. 

Pat: According to Safe Work Australia’s Managing Risks of Hazardous Chemicals in the Workplace Code of Practice, used or empty cylinders should be treated with the same precautions as full ones. That means keeping the valve closed, storing them upright, and ensuring they’re isolated from incompatible substances. 

Mel: So, let’s talk a little more about what to do with these containers and cylinders, especially when they’re no longer needed. What are some good storage practices? 

Pat: First off, empty chemical containers should be segregated just like full ones. That means keeping flammables away from oxidizers, acids away from bases, and so on. 

Mel: And the storage area should be cool, well-ventilated, and away from heat or direct sunlight. That way, you’re minimising the risk of any leftover vapours igniting or residues reacting. 

Pat: For gas cylinders, it’s important to keep them upright, secured, and isolated from incompatible gases. And remember—Class 2.1 flammable gases need to be separated by at least 3 metres from Class 2.3 toxic gases or Class 2.2 oxidizing gases. 

Mel: Now, when it comes to disposal, this is where things can get tricky. You can’t just throw these containers in the regular bin or leave them out in a scrap yard. 

Pat: Definitely not! For flammable liquids, the containers need to be cleaned, and then crushed or punctured to make sure they can’t be reused. With toxic and corrosive containers, it’s a similar process—cleaning, neutralising, and making sure that any potential for reuse is eliminated. 

Mel: And there’s a big emphasis on following the right disposal procedures for your local area. Some states or councils have specific requirements, so you should always check with your local waste authority or EPA. 

Pat: It’s also a good idea to return gas cylinders to the supplier whenever possible. Most suppliers will have a take-back program for their empty cylinders, and it’s usually the safest option. 

Mel: So what are the key takeaways here, Pat? 

Pat: The main one is: empty doesn’t mean safe. You need to manage these containers and cylinders just like they’re full until they’ve been properly treated. Follow the Australian Standards, keep them in a safe, isolated storage area, and use the right disposal methods. 

Mel: And when in doubt, always refer to the safety data sheet or consult with a dangerous goods expert. It’s better to be overly cautious than to have an incident. 

Pat: Absolutely. We’ve actually got a free eBook on chemical storage safety that goes into a lot more detail about these topics. Check it out on our website if you want to dive deeper. 

Mel: That’s a wrap for today’s episode! Thanks for tuning in, everyone. Stay safe out there, and don’t forget—empty containers can still be dangerous. 

Pat: We’ll see you next time on Chemical Safety at Work. Take care!