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Toxic Gas Cabinets

Hi I'm Jill, Chief Safety Officer with Vivid learning systems. I'm a former OSHA inspector and I'm here to help you identify and correct workplace safety hazards.

For this series we're at the University of Louisville in beautiful Kentucky to show you no matter where you work, safety is for everyone.

Do you work in a manufacturing facility or in a lab that uses toxic gas, and if so are you aware of an engineering control method called the toxic gas cabinet to keep you safe?

I'm here today at the University of Louisville with Kurt McKenna. Kurt is a staff engineer the micro nanotechnology Center and Kurt I'm wondering can you share with us what is a toxic gas how do you how do you define it?

So toxic gas is one that we're concerned about. A small leak it means it would be dangerous to standing right here right next to the to the cylinder if it did leak. So in our case this cabinet here is for a chlorine gas. A chlorine cylinder and that's one that if it leaks would be very toxic to everyone around. Another example might be silane is something we have which is explosive and if it interacts with oxygen so obviously, plenty of oxygen in the air can be very dangerous to anyone around. So the gases that we have here are toxic.

And so what's so special about this particular cabinet like what can it do or what are it what are its features? The key point with this cabinet is that it is enclosed and there's no way for the air inside to make it outside. So you can see at the bottom there's some ventilation slots that the air can flow in and it always flows out through the top here through this exhaust system there's no way for the air to come out once it's inside. It's at a negative pressure so that's a key point any kind of leak will never make it out into the environment around us. In addition to that there's a sensor in up above that will constantly taking measurements of the exhaust and will detect if there's any chlorine found in the environment and it also has a pretty sophisticated monitoring systems. Right exactly. Yeah that sensor is tied in with all the other gas cabinets we have that will trigger the hazmat alarm for the entire building if any of it is detected and so the sensors are part of a pretty sophisticated monitoring system. Exactly.

Yeah, it's about the monitoring system. We have several gases throughout our lab. Maybe about twelve different gas cabinets for different toxic gases. Each of those is hooked up to a central alarm system that will trigger a hazmat alarm. If any one of them detect a certain threshold of parts-per-million of that gas this one is specifically tuned to chlorine as opposed to other ones might be tuned to different gases so those will all if anything is happens it'll trigger that large alarm and everybody will know to evacuate the building, first opportunity. So then people will know that it's time to evacuate. Exactly get out of Dodge real quick. Right. Is it a special sounding alarm to let people know that it's a toxic gas? It's yes we have two distinct alarm one for fire and one for hazmat they sound similar, but distinct enough that you'd know that. So people know that as part of their training?

Yes. All right all right and so what could happen if you were using a toxic gas but it wasn't stored in a cabinet like this? The key danger with that is that a lot of these gases are in are dangerous in such low quantities that they're virtually undetectable before they're dangerous. Most of the time you'll be able to smell them, react to them at all you'll just get hit. So the idea with this is that it's enclosed and it's safe. If it were not then it would be potentially fatal or explosive. Even if a small leak, these cabinets are all also equipped with nitrogen so that it's inert gas that will flow into the cabinet if there is a leak that will hopefully dilute it and get rid of it if it does happen.

So when it's time to change out one of these toxic gas cylinders when you need more of that particular gas how do you do it and is that a particularly dangerous time it's, for all I'm scaring you it's actually not that dangerous of a time for us. These cabinets are all equipped to vent out the lines of any toxic gas and also close the cylinder for us before we ever even open up the cabinet so it's actually a fairly safe time. We already know that the cab or the cylinder is closed and that there's no gas in the environment because of the sensors in the exhaust so we can just open it up and remove the cylinder and put a new one right in. So the cabinet itself can turn the valves off on the cylinders.

Excellent, excellent and so who's allowed to open the cabinet to do it any of this changing out and how did you learn the right way to do it? Sure we're University so we have a lot of students here obviously working in our labs we don't allow the students to to change out these cylinders it's a potentially dangerous time even though it's made safe by these cabinets, we want people to know what they're doing so it's it's strictly staff only who will change these out and even for some of the more dangerous gas we can bring in professionals to come and change them for us.

Very good well thank you for sharing this really important information with us and this is good information for us to know as an engineering control method as we call it in the safety world to keep you and your employees safe from toxic gases.

I hope you gained a safety skill today. If you know someone who needs this go ahead and pass it on.

Safety is everyone's business.