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Bio Safety Cabinet

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.

Today we're at the University of Louisville dental school and we're talking about ventilation devices. Now sometimes we hear people call them hoods but that's just an assumption that all ventilation devices are the same, and we use this term called hood which really isn't appropriate. So to set us straight today and teach us about various ventilation devices that are used in labs we have Rachel Carry a lab safety training specialist here at the University and behind us is a biological safety cabinet.

Rachel can you share with us what is a biological safety cabinet I understand there's three different classes of them. So can we maybe start there. Sure a biosafety cabinet is a ventilation device set up in a laboratory to work with biohazardous materials. The primary function of the biosafety cabinet is going to be to provide containment to the hazardous materials that you're working with. Based on the potential risk of the material you're working with you may use one of three biosafety cabinets.

So we have a class 1 and class 2 and a class 3. Right now we're sitting in front of the class 2, it's the most common type of biosafety cabinet used in research facilities. What does the class 2 do like what sort of? So a class 2 biosafety cabinet is going to provide protection to the worker which is one of our primary concerns, but it's also going to provide protection to your workspace.

How do biological safety cabinets protect the worker? So airflow is going to be pulled in through front grille which you can see here in the front of the cabinet. Once it's pulled in its going to pass through a HEPA filter to remove any particulate from the air. That filter to air is gonna pass over your work surface and then it's going to be exhausted back through the cabinet where it's filtered again and then exhaust it out. That way you're getting protection to your workspace as well as to the worker and to the environment.

And so do all three classes have a HEPA filter and function that way or is that a difference too? They do all have a HEPA filter, but there are differences in how the air flow works or how the air flow passes through the cabinet. So in a class one cabinet ambient room air is going to pass over your workspace. So what you lose is the protection to your workspace. Okay however that air is still going to be pulled through the cabinet, pass through the HEPA filter and exhausted. Protecting you. Protecting the worker and the environment. Class two however is going to be filtered two times so a class two cabinet air will be pulled in filtered passed over the workspace filtered again before it exhausts. Could you give an example of what kind of work would happen in these kind of hoods. Yeah so at our organization employees or students typically use these for doing cell culture where they're growing mammalian or a variety of different cell lines for manipulations for different experiments that they might be working on.

Okay, and so it's important to protect the worker and the and the experiment that they're working on from contamination. Yes and these again are gonna be for biohazardous materials specifically.

Okay could you talk with us about things that you wouldn't want to do inside a biosafety cabinet what would be some unsafe work practices. There are a lot. So one of the most common problems that we see with people working with these cabinets are maybe bad habits that they form that could block the proper air flow within the cabinet.

So again we have this front grill we also have a grill in the back and as you can see from this cabinet here there are quite a few things stored in the cabinet, and what happens when you do that as you block the airflow through that fat grill? And what you're really relying on for protection is the airflow, which when properly functioning creates an air curtain that's going to protect you from any hazardous materials that may exit the cabinet and harm your body. And there's a there's a certain level to which the sash can go. You wouldn't want the entire thing open. Exactly and fortunately most of these are equipped with an alarm that will let you know if your hat if your sash is not at the appropriate level yeah.

And what about special cleaning considerations. Like what does an employee need to know about the way to properly clean it so they're not taking the decontaminant somewhere else with them. Yeah we do recommend that all of our personnel decontaminate the cabinet before and after use. After use to of course clean up your workspace after you're finished with it. But before you use it because these are shared as it is shared equipment and so you always want to ensure that you're getting started in a clean workspace. We also recommend that you decontaminate with a disinfectant that is it going to be effective against the material that you're working with. And there can also be other considerations such as the stainless steel workspace and avoiding the use of corrosive. Yeah, sure you wouldn't want to damage the equipment. Yes so you want to do a little investigating to make sure that you're using a proper disinfectant.

Can you share with us what kind of personal protective equipment would be important for employees to wear. For most of our lab spaces we recommend that employees always wear a lab coat and gloves and so that would apply as well when working in a biological safety cabinet, depending on the way that the employee is manipulating the material they want may want to wear more protective equipment. Including potential respiratory protection if a second layer of protection is needed. A impervious gown as splashes could occur during whatever technique they're doing. But typically a lab coat and gloves are standard. And the gloves the type of glove would be dictated by what it is that they're working with in there as well. Yeah a lot of people prefer latex because you can feel better with latex. Nitrile is what I typically recommend to people. It does in some cases add more protection and it's little bit more resistant to tearing which can happen a lot when you're working advise it right.

Exactly well thank you for teaching us about the first type of ventilation device we'll move on and now to another type of ventilation device commonly used in labs.

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.