Medical Waste Management – Session Materials

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Date of session: 09/26/2023


Aufra C. Araujo, PhD

Centers for Disease Control and Prevention

Didactic Speakers

Nikki Parrish, PhD

Associate Professor of Pathology, Johns Hopkins University School of Medicine

Director of Medical Mycobacteriology, Johns Hopkins Hospital

Aufra Araujo: All right, let’s get started. Good afternoon, good morning, and good evening, everyone. My name is Aufra Araujo, and I want to extend a warm welcome from the Centers for Disease Control and Prevention in Atlanta, Georgia. I am a PhD Health Scientist in CDC’s Division of Laboratory Systems. Thank you all for joining our eighth Extension for Community Health Outcomes, or ECHO, Biosafety session. The topic for this interactive discussion is Medical Waste Management.

Today’s subject matter expert is Dr. Nicole Parrish from Johns Hopkins University of Medicine and Johns Hopkins Hospital. To foster a strong sense of community and facilitate networking among biosafety professionals, we encourage everyone to turn on their cameras during today’s session. We understand that it may not be feasible for everyone, so please feel free to join with or without your camera. Our aim with the ECHO Biosafety project is to connect names with faces and build a community of practice. And I actually want to stop sharing for a little bit so I can see all of you.

As usual, if you can turn on your cameras, yay, I have a couple of people. I’m glad to see– oh, Naomi, nice to see you. Nice to see everyone. I would like to ask everyone a quick icebreaker question courtesy of Commander Sabrina DeBose on camera here as well. You know I always like to ask a question unrelated to science so we can start a more relaxed conversation. The question is, if you could have a superpower, what would you choose? So feel free to unmute and share your wish, what would be your superpower? If you cannot speak, feel free to enter it in chat. We’d like to hear from you. What would be your superpower? Sabrina, would you like to share yours? The other day you were talking about it.

Sabrina DeBose: Of course, Aufra. Hello, everyone. My superpower would be, I think to be invisible is what I said the other day. I think I’m going to stick with that one.

Aufra Araujo: Yeah, I like that. All that you could see and anybody else.

Sabrina DeBose: Yes.

Aufra Araujo: See you. That would be nice. A colleague of ours shared that her superpower would be to read people’s minds. I like that one too. I don’t know what my superpower would be. What about you? What would be your superpower? You up there in Zoom land. Any ideas? Aha, teleportation, so I don’t have to commute in Atlanta. I love that. That’s George.

Nicole Parrish: I second that one.

Aufra Araujo: Yeah.

Nicole Parrish: Traffic is awful up here in Baltimore.

Aufra Araujo: Mm-hmm, it would be nice just in a blink of an eye just move elsewhere and not have to commute and drive and all that. Nobody? Nobody would like any other superpowers? Like no limits, you could do anything. What would that be? Go back in time. I like that one, Marcia. I think actually I would go to the future instead of going back. I like always to look ahead, so I think I would go to the future.

Aufra Araujo: Wiggle my nose, and all the weeds would be pulled– I love that. All the weeds would be pulled out of my flower beds. That’s good. Control objects, freeze time, correct mistakes. Oh, that would be great. Maybe that’s a great reason to go back in time, to be able to correct mistakes from the past, go back, learn about it, go to the future and– go back to the past and correct those mistakes. I like that. You’d like super hearing powers. That’s good too. Maybe you can use those hearing aids some people– I don’t know. I never did. But I think, depending on how you adjust, you can hear a lot of chatter on those. So I heard.

Well, all right, if you think of any other superpower you’d like, please enter in chat. I love reading those. But in the meanwhile, thanks for participating in the icebreaker. And we all can laugh a little bit and get to the session, the more serious business now. Before we continue, I’d like to address some technical aspects of our ECHO Biosafety sessions. Please use the video capabilities of your device for this session.

Currently, all audience microphones are muted. When engaging in the discussion, please unmute yourself to speak. If you are experiencing technical difficulties during the session, please send a private chat message to George Xiang, who is labeled as CDC ECHO Tech. George will do his best to respond to your issue. If you are connecting to Zoom by phone only at the time of discussion, please introduce yourself by stating your name and institution before speaking.

How do these ECHO sessions differ from other presentations? These sessions are different from webinars in that the main feature is the discussion of case or clinical laboratory challenges. Our subject matter experts aim to share some applicable solutions that can be implemented in your individual laboratories. Our goal with ECHO is to bridge gaps, build community, and enhance biosafety. We encourage your active participation by sharing your knowledge and experiences. Each laboratory is unique, and your skill sets are unique. So your contributions to the discussion are valuable. Please participate. Here is a brief overview of today’s session. Let me share the screen again.

OK, I will introduce our subject matter expert Nicole Parrish, who will provide a didactic presentation and real case discussion. Then my colleague Sabrina DeBose will summarize today’s discussion. Closing comments and reminders will follow this, and we will adjourn this session. Actually, before that, I have some closing comments, but I’m going to do something different at the end of the presentation. So please do not drop the call. I’d like to share some survey results with you. So please stay.

Today’s session is being recorded. If you prefer not to be recorded, please disconnect now. Closed captioning is provided for this session, and you can find the link in the chat box. After today’s session, the transcript, the audio recording, presentation slides, and other resources will be posted on the DLS ECHO Biosafety website.

All right, now it is my pleasure to introduce today’s presenter. Dr. Nicole Parrish is an Associate Professor in the Department of Pathology at Johns Hopkins University School of Medicine and the Director of Clinical Mycobacteriology in the Special Pathogens Laboratory for the Johns Hopkins Medical system.

She received her PhD in Molecular Microbiology and Immunology from the Johns Hopkins School of Public Health and is Board certified by the American Board of Medical Microbiology. She is also the Director of the Disease Control and STAT Laboratories for the Baltimore City Health Department. Nicole, I’m so happy to have you here today. The floor is yours. And I will switch to your presentation.

Nicole Parrish: Thank you, Aufra.

Aufra Araujo: All right, now the floor is yours.

Nicole Parrish: All right, thank you, everyone. I think you need to go back to the first slide.

Aufra Araujo: Oh, no, I’m all the way in the end. Sorry.

Nicole Parrish: Oh, that’s OK. No worries.

Aufra Araujo: Gosh. All right.

Nicole Parrish: All right, well, welcome everyone. Thank you for joining us this afternoon, and what I hope to do this afternoon is talk a little bit about a unique experience that my laboratory and my staff had here at Johns Hopkins and how it pertains to everyday use of the autoclave as a sterilizing agent in the clinical lab and how we really changed the way we think about it because of our unique experience that we had. Next slide, please. So these are my standard disclosures. Next slide.

And so our unique experience– and I have to preface this by saying that I’m getting up there in years, and I’ve spent 30 years of my career in clinical micro. And suffice it to say, I’m very familiar with autoclaves. But as familiar as I thought I was, I wasn’t ready for what we were presented with back in 2014. So in 2014, you may remember that there was an Ebola outbreak in West Africa that revealed potential gaps in the abilities of, not only U.S.-based hospitals and laboratories to provide care, but just in general how weak things were globally.

Prior to this, care of these patients had been pretty much restricted to a limited number of facilities or biocontainment units. They were few and far between, and they were easily going to get overrun because there weren’t enough beds. So the CDC recommended that we take on a tiered approach because this was an imminent threat, and we had to come up with a plan. So U.S. hospitals were tasked with becoming either frontline healthcare facilities for those that did not have the capacity to take care of these patients.

Then you had the Ebola assessment hospitals where they could actually assess these patients. And then you had the higher-level Ebola treatment centers. And then Regional Ebola and Other Special Pathogen Treatment Centers were established in the U.S. They called these Regional Ebola Treatment Centers, RETCs. And we were tasked with developing one of these centers. Next slide, please.

So we have unique challenges because of this. Care of these patients, you may remember, and I’m sure that everyone on Zoom today is probably familiar with how much waste care of these patients actually generated. And it contained Category A infectious substances. So it’s not just the clinical care areas but also the laboratory medical waste was significant. And it exceeded our routine medical care protocols right out of the gate. So the CDC recommended that facilities preparing to care for these patients consider installing on-site autoclaves that were large enough to handle this Category A waste. Next slide, please.

So we established a biocontainment unit here at Johns Hopkins. They did this in record time. It’s a state-of-the-art biocontainment unit that can care for up to three to four patients. It is all negative pressure. We are now designated as the Region 3 Regional Ebola Treatment Center, and we serve Maryland, Delaware, Pennsylvania, Virginia, West Virginia, and DC. It has an on-site laboratory, and this was unique for us. We have a biosafety level three laboratory plus all of our microbiology laboratory site, which is located in the basement of one of the clinical care towers.

The problem is that the biocontainment unit is light years away from that laboratory. And so they decided to put an on-site laboratory within the biocontainment unit. And they also installed two pass-through autoclaves. So these are class B, which I’m going to talk about in a second, for sterilizing infectious waste. And it was designed such that all the waste was autoclaved before exiting the unit. Next slide, please.

So this is what the unit actually looks like. What you’re seeing is the common area, or what I call the Command Center, up front. And then down that long hallway are where all of the patient rooms are located. Next slide.

And we have a state-of-the-art laboratory located in there, which again generates a lot of laboratory waste. Next slide. And then you see the autoclave room proper, and there are two very large autoclaves that are pass-through. So what you’re seeing is quote, unquote, “the dirty side.” This is the area that is directly connected to the patient care and laboratory area. And then the pass-through goes through to a clean side where all of the waste that’s been autoclaved is emptied. Next slide.

So just a couple of words about autoclaves. I know everybody on this Zoom probably knows this inside and out. But just to refresh everyone’s memory. So there are class N and S autoclaves, which are gravity displacement autoclaves. So steam displaces a portion of the air in the chamber by gravity using a drain port in the bottom of the instrument. It can be used as a single application of steam, which that works in small autoclaves for flat medical tools. Or it can be used by multiple pulses of steam used for bagged waste and porous loads.

So most laboratories that I’ve ever been in have this type of autoclave. We even have some here at Hopkins, quite honestly, that are probably older than I am. They operate at 121 degrees Celsius using 15 pounds per square inch of pressure. And they’re pretty robust. They do the job well. We also have pre-vacuum autoclaves. Now, these are class B. And these utilize the power of a vacuum pump to remove the air from the chamber. And it can be a bit faster than the class N and S. It can sterilize most materials, and it can be also automated.

So some labs have this type of autoclave. You can get higher temperatures because your pressure is better at 132. Ours actually go up to 134 degrees Centigrade at 27 pounds per square inch of pressure. And so this is the state-of-the-art type unit that they wanted for the biocontainment unit. And the advantage to having the higher temperature, which is achievable because of the higher pressure, is that you can do shorter sterilization times. Next slide, please.

So I just am curious about the group that’s on the Zoom today. Does your facility autoclave laboratory medical waste? Just yes or no. I’m really curious to see how many because some labs have moved towards completely incinerating and sending out all of their waste. Some still autoclave some. Some it’s a combination of things.

So if everyone wouldn’t mind just answering the poll question, I just really would like to see how many people. OK, well, that’s great. 94% awesome. OK, let’s go to the next slide. So for those of you that autoclave waste, are you using class N or S, meaning just gravity-based instruments? Or are you using an autoclave that’s class B with a vacuum?

Let’s see. Everyone’s had a chance to answer. So let’s see what everyone said. So it’s a mix. And that’s kind of what we have here. We have gravity-based instruments, and then we have vacuum-based instruments. So that’s great. So this will play into some of our discussion down the road as we get towards the end of the talk. But keep that in the back of your hat, all right? So next slide, please.

So when we were initially approached to get this lab operational in the biocontainment unit, we were confronted with a daunting task because it dawned on us that we had to think about autoclaving large volumes of trash of all types. And so we had to go back, and we reviewed just basics. So just to rethink this, the purge phase is where the air in the sealed chamber has to be displaced. It’s either with steam that moves through the sterilizer or a vacuum.

Then the exposure phase is where the exhaust valves are closed off. The temperature and pressure inside stays static, and it’s at a desired set point. And then the temperature is maintained for a duration of time, whatever that tends to be. And then there’s an exhaust phase, and the exhaust valve is opened. Steam gets removed, and the chamber is restored to normal temperature. So these were all the things that everyone of us that had ever used an autoclave were familiar with, more or less. Next slide, please.

But as I said, once we started actually looking at the practice sessions that we were doing and these drills that we were doing for the biocontainment unit, we were familiar with laboratory waste. But we were not necessarily familiar with all of the waste coming from the patient medical rooms, whether they were the containment rooms themselves, the ante rooms for the staff to get ready to go in and out of the patient rooms. And that if you had a very ill patient that was generating large volumes of waste, including liquid waste, then you really had to definitely think about this because all of the waste ended up in the autoclave room together. And we’re thinking, OK, we have to figure this out.

So the amount of waste initially we realized was too great to permit segregation of lab versus patient waste. And if you think about it, all of the protocols that we use in the microbiology lab, from the beginning of my training to the current time, said that 60 minutes at 121 degrees Centigrade to 131 degrees Centigrade will kill most microbes, OK, without regrowth. There’s data that’s actually shown you get an average 8-log reduction at that temperature and time. And that doesn’t include your ramp-up or your cool-down stages. So that’s 60 minutes of strict exposure. So we thought, OK, so let’s see if all of the waste, so waste from the laboratory, waste from the patient rooms, can be placed into these autoclaves. We’ll try the standard cycle at 60 minutes and see where we go. Next slide, please.

So having said that, based on your own experience, do you think that the 60-minute standard would be good enough to sterilize the simulated medical waste loads from the BCU? OK, let’s see what everyone thinks. Yes, and that’s what we thought. I’m glad to see that everybody thought that this would work because that’s what we initially thought. And I have to tell you all a funny story.

So of course, Murphy’s law said that our biocontainment unit would be completely operational and ready to go when we were headed to the ASM meeting in May that year. And of course, we had everything ready to go. All the drills had been done. But the autoclaves were not completely validated yet. And I’ll get more to that as we go through this talk. And don’t you know, the first patient ended up showing up in our emergency departments while we were all at ASM without our autoclaves being completely validated. So next slide, please.

So these were the initial factory default autoclave parameters. So you had sterilize times of 30 minutes for your gravity and liquid cycle and 15 minutes for your vacuum. And you can see the difference in temperature. And these were, at that time, state-of-the-art high-tech autoclaves that really got the job done. But even with that, I thought, well, we’re going to go for 60 minutes. Let’s just see what we get. And we also tried all of the default parameters. So next slide, please.

And we used all the standard indicators. So we used autoclave tape on the outside of all the runs. We used our biological indicators, which you’re all familiar with, plus the rapid tests and the embedded tests. And don’t you know that 16 of 19, or 84%, of the runs that we did using the factory default settings failed to sterilize biological indicators in the center of each of the simulated loads. And these were mixed loads largely in the very beginning. And so, 30 minutes didn’t work, and we constantly were calling the autoclave company, the manufacturer just to make sure that we didn’t have any kind of issues with the settings and that everything had been installed properly. Next slide, please.

So all of our failed runs initially included all the runs performed using liquid or gravity cycles for 30 minutes at 123 degrees. Next. It included all the vacuum runs at 134 degrees for 15 minutes. And I have to say that a lot of the tech support individuals that we talked to at the autoclave company actually were surprised that we were getting run failures. OK, next please.

The simulated loads included– now, we were trying to mimic everything we could conceivably think would come either out of the patient rooms, out of the ante rooms to the patient rooms, or out of the laboratory. So all of our simulated loads included liquids of 0.5 mLs to a liter, all of the PPE, the paper products, all the other waste, all the laboratory waste, saturated or unsaturated linens that were used. Next, please.

Failures occurred regardless of the type of bag closure. So this was a big issue. Initially, they really were adamant about making sure that the bags were closed after. They left the patient rooms because they had to transit the hallway getting it down to the autoclave room proper. And that was true for the lab too. The lab is located at the opposite end of the BCU. So they had to get the trash into these wheeled garbage cans. They’re like big Rubbermaid garbage cans with lids. But they were worried that if they ever tipped over and the bags weren’t closed that you would have a contamination event and expose all of the personnel. So we tried different types of bag closures, gooseneck, lightly folded, or rubber banded. And those all failed. Next, please.

And then they came up with an idea that they thought, maybe we could use dissolvable autoclave bags, you know that you could tie and secure very tightly transiting them down the hallway. But then once they got into the autoclave they would dissolve. That was a disaster. That’s one of those things where I like to say don’t try this at home. This is not good. So we abandoned that because any liquid at all would cause them to disintegrate. Next, please.

So what we needed at the end of the day was a sterilizing parameter which provided for the shortest turnaround time because of the large volumes of waste that were being generated but could be used with mixed-waste loads. The question was, what could we mix, and how did we validate that these were actually getting sterilized? And we knew that we couldn’t segregate laboratory versus patient waste. It just wasn’t– first of all, it’s not safe. Second of all, with the amount of waste that’s being generated, it’s just too cumbersome to do that. And then, of course, we had to do this while wearing enhanced PPE under BSL-3 conditions. Next slide, please.

So these were autoclave parameters that we actually modified from factory default settings, and this list is just to show you things that we actually tried. So we changed the sterilizing time between 15 and 180 minutes. And that was tried based on the load type, whether it was laboratory waste, linens, saturated linens, or whether it was just paper products or whatever, and then liquids. Sterilizing temperature was tried ranging from 123 to 134, rapid or slow exhaust. And then the purge time, the pre-charge, and number of pre-vacs were all tried at different levels to see what worked the best. Next slide, please.

So based on your own experience, do you think we were successful in finding a single cycle, because that was our goal initially, and parameters which provided for decontamination of all medical waste considered together? So that would include laboratory waste, paper-based waste, liquid-based waste, and all other patient waste.

All right, well, the no’s have it. And I have to say that we really tried very hard to find a number of parameter settings that would work for everything so that, no matter what, the people that were working on the unit did not have to overthink how they were putting waste in the autoclaves. Go head to the next slide.

So these are our optimized cycles and parameters that we ended up with. And you can see that the sterilizing temperature was 134 for our vacuum settings. And we ended up PPE and dry trash was segregated from saturated linens. And what ended up happening was that if they had a lot of PPE and dry trash, they would run a 30-minute cycle. If they had saturated linens only, they would run it on a 60-minute cycle. And then liquids, unfortunately, had to always be done separately because the biological indicators that we embedded in the middle of these loads just never sterilized.

And that included, I don’t know– and we can chat about this at the end– if any of you have experience with using solidified tires for large volumes of liquid. The interior of the solidifier never ever sterilized unless you went to extreme time points, like 120 to 180 minutes. But you can see that this is what we ended up having to adapt to make sure that nothing was infectious that was coming out the other side. And of course, this is an extreme case. We’re talking about Ebola. But this also has interesting ramifications for just general use in the laboratory. Next slide, please.

So before I ask you this question, it caused us to think about, well, wait a second. We have passed through autoclaves in our BSL-3 units. In our laboratories, we have standard autoclaves that are used for medical waste in other areas of the laboratory that are BSL-2. Are we doing enough? Are we doing the proper thing with our validation of these units and our quality control in general? So do you think it necessary to utilize simulated loads of medical waste for validation of autoclaves used in laboratories for general decontamination purposes?

All right, let’s see. Well, I’m happy to see that because, even when we started embedding– and it’s interesting because we developed this little trick where you take your biological indicator. You put it in the middle of your simulated load, whether it’s an orange bag filled with laboratory paraphernalia or whatever. And then you attach a string to it, and you’re able to remove it that way once the load is finished. And then you can check to see if the very interior of the bag actually got sterilized.

And for all intents and purposes, if the load is packed correctly, it works. If it’s not packed correctly or the bags are sealed or folded over too tightly, it doesn’t sterilize. And that was eye-opening to us too in our own lab because sometimes people fold the bags over tightly, and then the steam can’t penetrate. Next slide, please.

So what about for autoclaves used for decontamination of medical waste? Would you say that we really should do simulated loads for those? And for those of you who said no to the other question, it’d be interesting to see what you think if you’re dealing with highly consequential pathogens, including Category A.

All right, let’s see. Yes, OK, that’s awesome. And I think, from my perspective, I’m erring on the more conservative side now based on what we’ve been through. Just knowing what I know now and seeing how many loads actually even failed at the 60-minute mark, when 60 minutes is typically the gold standard for the industry at 121 degrees, and we all think of that as being the file safe. You don’t even need to think about it. But that’s not necessarily true. Next slide, please.

So I’d really be interested in having a short discussion about everyone, your own experience using autoclaves, and if you’ve ever encountered this kind of problem or just interested in hearing about your thoughts on this. And I thank you for your attention. And I don’t know if anyone has anything in the chat. What I didn’t mention while I’m finishing up here is that, when we do our quarterly QC– so we do a quarterly– we do a monthly QC with biological indicators for all of our autoclaves that we use.

And then quarterly what we do is we’ll do the same thing with a simulated load, where we actually bury the indicators inside of the simulated load just to make sure that everything is as it should be because one thing that we did find is that you can place your biological indicators in your autoclave tray, and they’ll pass. But it doesn’t necessarily follow that everything that’s in your biohazard bags, that’s in the autoclave tray for autoclaving will pass. And we found that.

So we had instances where if the bag was not– all of our trash is double bagged. But if it’s double bagged and it’s sealed too tightly, we had instances where the bagged trash did not pass, and the autoclave or the biological indicator in the tray itself did. So it really caused all of our laboratory technologists to review what they were doing and not haphazardly just fold the bag over so tightly that you pop it in the autoclave. And that goes even for BSL-2 trash just in general because we were finding that the steam actually was not penetrating.

Let’s see. There’s a couple things in the chat. Can you put the question back up?

Aufra Araujo: Yes, Nikki, thank you so much for your excellent presentation. Very informative. And George put the question back up in chat, the question from your last slide. While people are thinking about their questions, I’d like just to get started with one question for you. And we discussed this some time back when we were talking. I’m certain that most laboratory professionals know that the laboratory waste regulation varies in each state and sometimes even within different counties in the same state.

So it is important to validate your own parameters and develop your own laboratory SOP in waste management guidance. So my question is twofold. One, are you familiar with some areas where the federal and state regulations differ specifically between states or even specific counties within a state? And my second question is just maybe highlighting the importance of validating your autoclaving waste, your laboratory waste decontamination autoclaving process. So if you can talk a little bit about that. I know you discussed your validation experience. But if you can just highlight the importance of doing that for BSL-2 labs, for instance.

Nicole Parrish: Right, well, as far as regulation, I can’t think of any specific examples. Although, I’m sure that they’re out there because I know that different institutions have differences. For instance, when we were developing our protocol for the biocontainment unit, we relied very heavily on partners that we had or experienced that other facilities had doing the same types of things. And it really depends on the type of autoclave you have, what the default settings are, what the parameters are, what the instrument is capable of because, for instance, we found that there were other units that were able to do a 15-minute autoclaving session and get sterilization of certain types of trash.

But again, it was a different autoclave than we have. The chamber size really plays into that a lot on whether you’re using a pressure-based versus a gravity-based system. So all of those parameters really caused us to examine this from a different perspective than we had been used to thinking about. And I think it’s a learning experience, right? If we had all the answers, we’d all be out of jobs. So we don’t have all the answers, which is a good thing. So I’m still in my career 30 years plus now. And I’m still learning stuff every day. And so you realize, well, maybe it’s not that simple.

And what I really like about having gone through this is that, even in our BSL-2 and BSL-3 lab, we actually changed our practice. We re-examined how our trash was getting autoclaved, how it’s loaded because the tighter– our bags are packed maybe 50% to 75% full, no more than that. They’re not up to the brim now because sometimes– and we use very small buckets, like small waste buckets to put the bags in.

And those get loaded into the autoclave, and the loads are controlled and in terms of the individual size and the buckets, how much is in the bag because, at the end of the day, even the way the bag is folded over really plays a role in whether or not you are getting everything sterilized. And especially for Category A, we really want to make sure that everything is sterile coming out the other side. So that’s been a huge thing for us.

Aufra Araujo: Yeah, thanks, Nikki. There is a question in the chat. Did you use pre-vacuum pulse for liquids during your validation of the different load types?

Nicole Parrish: Yes, we ended up doing pre-vacuum pulses. And actually, in that last table, I think it does list that. Let me just double-check. And the liquids were really the most problematic out of everything that we did. But that’s not surprising because liquids are a big hassle. I don’t know how many people actually on this call actually have to deal with large volumes of liquids. We ended up using three pre-vacs for our liquid cycle.

Aufra Araujo: Good, Rolinda, would you like to ask any further questions about that or share from your own experience?

Rolinda Bailey: Hi, everybody. Thank you. I just was wondering if the liquid overflowed when you use the pre-vac because normally, I know for us at our facility, we don’t use pre-vac on liquids, but that’s mostly for media prep. It’s not for this type of purpose. So did you just have anything that was a liquid sitting in a pan that would catch anything that overflowed?

Nicole Parrish: So the liquid was actually put into– and that’s a great question, by the way. So we would actually put some sort of absorbent materials, usually paper-based, in the bottom to line a double autoclave bag. Put your liquid container in there. At times, we would also try to use absorbent, I call them, diapers or whatever. And then we would use those.

And then if it spilled over, then what was– and usually these were suction type canisters that had been used on patients or buckets that had been used for waste materials that had a lot of liquids or whatever. And they did spill over, but they were contained in the bag. A lot of it got sopped up by the actual absorbent materials in the bag. And then if that failed, they were in a tray.

Rolinda Bailey: That is very helpful. Thank you so much, Nicole.

Nicole Parrish: Yes. The concern was with these Ebola patients you have large volumes of vomit. Potentially, you have large volumes of all kinds of other liquid-based waste. And so that was a huge problem. In the laboratory, we’re a little bit more controlled. We could control some of the liquid waste. But we were tasked with doing the whole thing. So we had to figure it out.

Aufra Araujo: Great. Nicole, there is another question in the chat. Do you have a state entity that permits your regulated medical waste treatment activities? And were they involved in the development of your autoclave validation procedures?

Nicole Parrish: So the state, in this case– so all our downstream processes were based on Stericycle, which all of you are probably familiar with. And we have a local Stericycle here that basically picks up all of our medical waste. Where the state got involved was whether or not it was sterile coming out the other side, and this was specifically for the Ebola issue. So we had to demonstrate that this had been done to their satisfaction before they would allow the waste to be taken off-site. But I don’t know that would necessarily happen unless it was under these extreme conditions because in my experience they had never been involved prior to that.

Aufra Araujo: Great. David Hill, do you have any follow-up? That was your question. I see, OK. Thank you.

David Hill: Yeah, I don’t think so. Hi, everyone. This is Dave. Yeah, I just know here in New York we are permitted for treatment, and we also send our materials out with a permanent hauler. But we’re also required to be permitted for high containment labs regardless of that.

So I didn’t know if the state, even though you were sending things out, sounds like they still wanted to approve your validation methods and make sure they were comfortable with that before the Stericycle.

Nicole Parrish: As far as the higher-level permits and whatnot, we do have your standard permits and whatnot. But this was a degree of oversight that we were not used to for that particular instance. And then, of course, all of the waste is tracked. You have barcoded labels on everything leaving here so that everything can be backtracked to the source. So it was quite the learning experience.

David Hill: OK, thank you. I appreciate it.

Aufra Araujo: Can only imagine, Nikki. So now that post-Ebola outbreak and post-pandemic, can you talk a little bit about regular– now it’s kind of back to normal. So can you share how these experiences you had during the Ebola outbreak has influenced your lab, Like moving forward on a daily basis, or has it? And if so, how?

Nicole Parrish: Yeah, I do think it has impacted us, especially with regard to the BSL-3 lab and the pass-through autoclave that we have in our BSL-3 facility because we actually do our quarterly QC, which was added just to make sure that the units are operating the way they should, using simulated loads. And we do that just to make sure, for our own peace of mind, that we’re able to sterilize everything coming out of there.

From the perspective of the standard microbiology laboratory, I think we just reminded everyone don’t fill your autoclave bags or your trash that’s headed to the autoclave more than 50% to 75% full. If it’s jam-packed, then the center of your load may not necessarily get sterilized. And that’s a big problem. It’s just little things. It’s tweaking what we already did, but just making sure and putting out little reminders in the lab notes for everyone just to make sure that they all knew.

Look, if you have 100 plates, don’t stuff them all in one bag brimming to the top and then tape the thing shut at the top because it’s really critical that the actual steam get in there in order to kill the organisms that are present. And I just think it’s just one of those things that we use all the time and you don’t think about. And we were forced to think about it. And being forced to think about it, we learned. We learned a few tricks and a few things that we should be cognizant of.

Aufra Araujo: OK, agreed. I know we have some colleagues from overseas. I’m not going to call any names, but I’m curious if– I’m curious about anybody. But since I see some names and colleagues who are from overseas, I wonder if they have anything they would like to share from their experience overseas on how they manage the laboratory waste in their area? No pressure, just if you feel like there is anything you’d like to contribute to the discussion.

OK, while people think about it, I just thought of another question, Nikki. Do you know of any safeguards to prevent illegal dumping of mishandling of medical waste?

Nicole Parrish: Any safeguards? No, I actually do not. I know it happens, and it’s a little scary. But it definitely does happen.

Aufra Araujo: Do you know what are the consequences if there are violations of that kind?

Nicole Parrish: I don’t, but maybe someone else on the call might. Does anyone on the call know?

Joey Stringer: Hi, this is Joey in Dallas. I would think it varies from state to state, county to county, what that law would be.

Aufra Araujo: Do you know what is the consequence, David, in your area?

Joey Stringer: No, I don’t. Other than a fine, I don’t know exactly whether it’s a criminal or monetary fine.

Aufra Araujo: Interesting. Thanks, David, for chiming in.

Joey Stringer: Well, I do have another question, Nikki. Do you still double-bag your trash?

Nicole Parrish: Our BSL-3 trash we do.

Joey Stringer: OK, because we don’t double-bag ours. We have a pretty thick VWR bag.

Joey Stringer: I’m just curious.

Nicole Parrish: Yeah, standard BSL-2 we don’t.

Joey Stringer: All right, and because you talked about early on how the autoclave wasn’t working that well. Was it the packaging of the package that wasn’t working well more so than the actual autoclave not working?

Nicole Parrish: So it was, initially, we were trying to put all types of trash in one load because that’s what was really going to be optimal.

Joey Stringer: Right.

Nicole Parrish: We could not include the liquids because that was a problem. And then you have all the bed linens on top of that. So if it’s just laboratory waste, 30 minutes would have been sufficient with the autoclaves that we have. But because we always had other things to consider, and that’s why the type of load that you have is really important and how it’s packaged.

And so we had to come up with a way to target as much of the trash as possible together in one load, and that’s why the PPE and the paper products and the patient waste, aside from the liquids, was combined with the laboratory loads so that we could at least– and that worked for 60 minutes. The laboratory waste– because some of that also included some liquids, not like you would have with the patients. But it did include things that required a little bit longer to get sterilized. So that’s why we went from a 30-minute cycle for PPE and paper and those types of things coming out of the patient room to a 60-minute for that plus the laboratory waste.

Joey Stringer: Yeah, all right, good. Thanks.

Aufra Araujo: Excellent, I see another question in the chat, Nikki. Is there any alternative to biological indicators to rapidly determine if a disinfection or sterilization process has been effective?

Nicole Parrish: Well, in my view, unfortunately, there isn’t. But here’s the good news. The biological indicators used to require that you run them through the cycle. You then have to incubate them for at least 48 hours. And now, there’s actually a three-hour biological indicator. So it’s pretty rapid, and it gets you an answer same day. So that’s much better. The tape only tells you if it gets to the proper temperature, and it really doesn’t tell you if it’s sterile or not.

Aufra Araujo: Yep, I agree 100%. So that was an excellent discussion. We are getting close to time. Thank you, everyone, for participating. Thank you so much, Nikki, for this thought-provoking, challenging presentation because, from my own experience, I did some work with laboratory waste at CDC. And I know people sometimes take for granted that the waste will be decontaminated and everything is fine. So it’s a very important topic, and it’s also dear to my heart.

Now, I will invite my colleague Commander Sabrina DeBose, who is the Safety Team Lead in the CDC Division of Laboratory Systems to provide a summary of the discussion from today’s session. Sabrina, over to you.

Sabrina DeBose: Yes, thank you, Aufra, and thank you, Dr. Parrish. Let me start from the beginning. I was just talking to you all. So I want to say thank you all for the presentation today, Dr. Parrish. That was a great and timely discussion on decontaminated medical waste, sorry, medical waste management. I will summarize the discussion. So we did have a lot of discussion going, and we do appreciate that. And let’s see.

One of the first points that we discussed, the federal and state regulations, Dr. Parrish provided her experience about other facilities doing the same work and highlighted that it does depend on the type of autoclave that you’re using. The parameters can cause them to be examined from a different perspective, and you should also look at the type of waste that’s in the autoclave.

Another point that we talked about is highlighting the importance of validating the autoclave waste for BSL-2 laboratories. And it was suggested to reexamine how waste is processed. Loads are controlled. You should consider how much is in the bag, and that does play a large role to ensure that the waste is properly autoclaved.

Another question we had in the chat, do you use pre-vacuum pulses? Dr. Parrish shared her experience about using pre-vacuum pulse for their liquid cycles. And we also had a follow-up question about liquid overflowing when using the pre-vacuum cycle. And it was suggested that, yes, it is possible. But you should use a double liner or an absorbent diaper to absorb the spill. Another point of discussion was about the state entity that permits regulated waste.

Dr. Parrish shared that the Stericycle picked up the medical waste. However, during that time that she shared the didactic experience with us, the state wanted to ensure that the waste was decontaminated before it was picked up by Stericycle. And typically, that’s not their normal process for the state to be involved in the waste. So it was a learning experience, but she shared that was not their typical process.

Another point to bring up during the discussion, someone reminded that the laboratorians– oh just to remind laboratorians of the standard techniques when managing waste, such as basic concepts. Don’t fill your autoclave bags with waste because the center of the bag may not get sterilized. And also ensuring not to completely seal the bags during the autoclave. So it’s just a constant reminder just to remind the laboratorians of the basic processes when handling waste.

Another point to bring up, safeguards to prevent illegal dumping of medical waste. And we didn’t have anyone on the call that was aware of any type of safeguards that’s available. One of the participants did suggest that it does vary by state to state. And no one was sure or we did not have anyone that’s aware of any of the consequences. But once again, the consequences for the action does vary from state to state.

One other point that was brought up during the discussion about double bagging waste, Dr. Parrish shared that it is standard practice to double bag their BSL-3 waste, but it’s not common practice to double bag the BSL-2 waste. And that is it for the discussion for this topic. Dr. Parrish, would you like to add any other additional details about the discussion points that I may not have covered?

Nicole Parrish: No, I think you captured it pretty well. I did see one final comment in the chat from someone saying that true indicating has a self-contained biological indicator that also has a tablet which returns a 30-second pass/fail result. And this person said I don’t have a lot of experience with it but have run a few compared to the 3M test. That would be– I don’t know. I have not worked with that indicator, but certainly, if it’s a 30-second pass/fail, that might be worth looking into to just to speed the process up.

Aufra Araujo: And remembering to validate it with loads similar to the loads they run in their laboratory. Yes, thanks for sharing that, Corey, I think. Thank you so much, Dr. Parrish, and Sabrina for this summary. As I promised, I would like to share with you very briefly the survey results from– yes, OK. I keep asking you to respond to our surveys, post-session surveys. I know we have a lot of. Surveys this is the summary from the survey respondent’s feedback at six months.

So these are some of the results from the responses we obtained from 25 participants who completed the six-month follow-up survey. This is a low response rate this is 25 out of 78 of you who attended at least one session. I wanted to be transparent and share with you the results. If you don’t agree with these types of responses, there you go. If you respond, we’ll be able to address your suggestions for improving these sessions. So these are sessions from January through May. You see there on the left the title of the sessions.

On the top left graph, the question was, “I can discuss biosafety challenges I encounter” on each of the topics listed to the left. And you see the responses there. About 47% of the respondents said “yes” for the first session, Public Health Laboratory Burnout and Effect On Safety, that was run in January. And you see all the other responses there for that question.

Then I’m going clockwise, the graph on the top right, “I feel empowered to communicate acquired laboratory safety knowledge.” It’s kind of mixed, but I think the majority said yes to Risk Assessment in Clinical Laboratories, the session run in February. And the session in May, PPE Use, and then everything else right there in between. Going to the bottom right, “I used the information from this session to identify biosafety areas for improvement.” 50% of respondents said “yes” to Risk Assessment in Clinical Laboratories.

I’m excited about this response because this is one thing that we find is very important because a lot of the biosafety-related questions, the answer is, it depends. It depends on what? Depends on risk assessments. So I’m glad to see that 50% of the respondents feel that they can use the information they learned on that session. And actually, all the sessions, in general, respondents feel they can use that information to identify biosafety areas for improvement. We have 50% for the session on Risk Assessment, and then 46% for the PPE, and followed by 44% for the Decontamination of Laboratory Equipment, and so on.

And then finally, on the question, “I reviewed the current processes and procedures to determine if they are up to date.” I’m also excited about the responses here because on the PPE session, a majority of respondents said they review their processes and procedures based on what they learned or the discussions during that session. So I’m curious, what do you think, if you attended those sessions, what do you think about it?

You don’t need to respond now, but if you feel so inclined while I’m talking, preparing to close the session, feel free to enter your thoughts in chat. And for the session in October, we are going to run the survey a little bit differently. We are going to run after the session. So instead of you listening to me asking you to please, please, please complete the survey, you have just a few minutes to respond to the survey. And we’ll see if you like that better.

So with that, I finish my spiel on the survey. And I would like to talk about the session in October. We are excited to have our next session on Tuesday, October 31 at noon. So on your Halloween lunch or evening or breakfast, depending on where you are, we have the pleasure to have Jill Power talk about Quality in Biosafety. Jill is the former Deputy Laboratory Director for New Hampshire Public Health Laboratories. She retired recently, but we are very lucky to have her agree to come and talk with us about Quality in Biosafety. She will have a very interesting presentation and case discussion.

So please visit the DLS ECHO Biosafety website to view all upcoming sessions. And I’ll stop here. One little brief comment I have, you all must have heard about the potential for government shutdown. I’m being optimistic. We are all optimistic here. If there is a shutdown, I hope we will be back by October 31, and we will have our ECHO session. But you all on the ECHO Biosafety distribution list will receive an email from us if we are having the session.

If we are in shutdown, we won’t be able to send you an email, and that’s a sign that we won’t have the October session and that we will have to be rescheduled. But like I said, we are all thinking positive here and hoping that the session will occur as planned. With that, I will adjourn.

Thank you so much for attending and thank you for your participation. Nikki, again, thank you so much for a productive presentation and discussion. We are adjourned now, but I ask Nikki and the Biosafety Team to stay on the call. Thanks, everyone. Have a nice rest of your day.

Additional Resources and Related Publications 

  1. Centers for Disease Control and Prevention. (2016, December 1). Packaging and Transporting Infectious Substances.
  2. Centers for Disease Control and Prevention. (2017, July 24). Specimen Collection and Transport Guidelines for Suspect Smallpox Cases.
  3. Centers for Disease Control and Prevention. Specimen Storage and Shipping Guidance.
  4. Garibaldi BT, Reimers M, Ernst N, Bova G, Nowakowski E, Bukowski J, Ellis BC, Smith C, Sauer L, Dionne K, Carroll KC, Maragakis LL, Parrish NM. Validation of Autoclave Protocols for Successful Decontamination of Category A Medical Waste Generated from Care of Patients with Serious Communicable Diseases. Journal of Clinical Microbiology, 2017 February; 55(2): 545-551.
  5. Karthik K, Babu RPA, Dhama K, Chitra MA, Kalaiselvi G, Senthilkumar MA, Raj GD. Biosafety Concerns During the Collection, Transportation, and Processing of COVID-19 Samples for Diagnosis. Archives of Medical Research, 2020 October; 51(7): 623-630.
  6. U.S. Department of Transportation. Transporting Infectious Substances Safely.