Podcast: Surrogate Testing Saves Money, Materials And Lives

July 13, 2021
The proper selection and operation of contained dust collection equipment is critical for a host of reasons.

The use of surrogate testing is a valuable tool in ensuring that contained dust collectors are meeting several requirements including environmental, employee health and safety and production cleanliness and efficiency.

Chemical Processing spoke with David Steil, pharmaceutical market manager at Camfil Air Pollution Control, to better understand surrogate testing. David has a Bachelor of Science degree in safety and industrial hygiene. He spent more than 12 years with Wyeth Pharmaceuticals as a member of its corporate environment health and safety group. David is a member of the International Society of Pharmaceutical Engineering and the American Industrial Hygiene Association.


Q: Can you explain surrogate testing? Obviously, in theory, it's pretty easy to grasp. But there may be some nuances that we don't understand, can you go further into that?

David Steil

Pharmaceutical Market Manager
Camfil Air Pollution Control

A: Yeah, there's a lot to it. And if I had to make an initial recommendation, it would be to hire a professional consultant if this is going to be your first surrogate test. I think it would be very beneficial to hire a consultant that's familiar with all this because there is a lot to this. There's a testing protocol that needs to be developed. There's the testing space that needs to be very specifically designed, then there's the equipment to be tested and how to place it in its proper configuration. There's just a lot to it. So the "ISPE Good Practice Guide" that's available is a good starting point. It'll help folks get familiar with surrogate testing and what it's all about and why we need to perform this type of testing. But I definitely would recommend, if you had the means to do so, is to hire a professional consultant that is familiar with this so that they can make sure that all these little details and nuances are being covered such as the testing equipment, as I mentioned before, is set up appropriately, excuse me. The location of the testing a dedicated area with restricted access. The vendor needs to put together procedures to be undertaken when performing the surrogate testing, so there's a lot to it.

Surrogate testing is a great tool to really help to understand the performance of equipment. A lot of this containment and isolation equipment can be extremely expensive. So, of course, you want to be sure that you're getting your money's worth, that you're getting what you paid for. So this type of testing is definitely going to help to do that and to help to identify if this specific piece of equipment or even the entire process is appropriate for what you're looking to accomplish.

Q: Now, this isn't just for pharmaceutical industries, there's other industries this would apply to as well, right?

A: Absolutely. Pharmaceutical is probably one of the premier ones because there's a lot of potentially hazardous or toxic materials that are being handled in that industry, but certainly for metalworking and various other industries. Making sure that the proper isolation and containment equipment is being used for each application and definitely identifying which materials have the potential to be hazardous in the workplace and making sure that they're properly contained, properly controlled so that we're not adversely affecting the health of the employees and the operators working in those areas. So there's many different industries that could benefit from this other than the pharmaceutical industry.

Q: You touched on it a little bit, but I want to get a little bit further into it, the benefits of surrogate testing, what are those benefits?

A: Yeah, so this type of testing provides the ability to really validate the effectiveness of the isolation and containment equipment prior to the purchasing process. Okay? So it really allows the end-user to compare similar pieces of equipment basically, an apples-to-apples comparison to determine which one's appropriate for each specific application. The selection of equipment now can occur during the design and engineering phases of projects, which can help dramatically reduce lead times which, of course, always is an issue. This information can also be used to generate a list of acceptable vendors and equipment suppliers that meet the safety and industrial hygiene guidelines of your company. So again, you can have this list that's there, you know who's completed the testing and which pieces of equipment, and which suppliers really meet your needs for these types of applications. And, of course, with all this information available, I hope, of course, to save time and money with regards to design consultants and contractors because you've already completed this work ahead of time.

Q: How do you select the equipment and or process to be tested? Is there anything else we need to know about the selection process?

A: Yeah, I don't want to say that's the easiest part, but I think you'll know that pretty quickly upfront you'll be looking into purchasing a piece of equipment or a process that you're looking to control, potential exposures to employees or operators. But it is probably the most important element of this because obviously, this is what's going to drive the test and how you're going to perform the test and all these other things. So it can be a specific piece of equipment or the entire process. But really identifying that equipment upfront, and then all the specific activities, or access points, or interactions with that equipment also needs to be reviewed. All of this really needs to happen, obviously, prior to the testing. But you can definitely make adjustments as you move through the testing. You'll have your protocol in place but it's really not etched in stone, there is flexibility there, that as you start going through the testing, that if you identify some issues, definitely make note of them but you can make adjustments as the testing moves forward to really make sure that it's accurate, and make sure that it's really applicable to what you're trying to accomplish and it's going to reach your goals at the end of the day.

Q: I'm trying to picture what takes place during testing, what types of activities or operations are completed? Is that the entire process?

A: Yeah, great question. Typically, this is defined in the testing protocol. So ahead of time, you'll sit down with the contractor, or you'll sit down with the "ISPE Good Practice Guide" and kind of go through and really identify what you want to do ahead of time. But it's really looking at the actions to be carried out by each individual operator. You know, do you want to look at typical workplace operations versus a worst-case scenario? Duration of the testing activities also needs to be determined. And that's typically done based off of the proper operation of the equipment and/or the process. So it's really identifying each of those steps if that hasn't been completed. Typically, that is done ahead of time because it's equipment that most of the time is typically in operation. But it's really identifying all those steps. How many people are going to be involved? What specifically do we need to look at? What are the hotspots, I guess we could call them where, okay, we're doing a mechanical transfer, or we're doing a transfer of material, where there's a high risk for potential exposures?

Functional testing should also be included, this really ensures that the system is functionally acceptable, does not hinder the use of the equipment by the operator. It's fine if you have containment and isolation, but if you can't operate the equipment properly, or if it's just such a pain in the neck or just so difficult to use, it kind of defeats the purpose. Okay, if that makes sense. So it's really looking at not only the proper functionality of the equipment that you're isolating or containing, but also making sure that it's functionally acceptable and that, okay, this is something that we can do and that the operator, or whoever's interacting with the equipment, is going to be able to do. I don't want to use the term easily, but it needs to be easy enough that they're not going to want to defeat these types of processes.

Q: Do you mimic the environment which these will be...say if you're down in Georgia, and it's really hot and humid. Or if you're up north in Detroit, and it's a cold winter, do you put those into consideration as well, those types of...?

A: Yeah, that's a fantastic question. Typically, with the surrogate testing, we'll actually do this in a controlled environment, okay? And you can...you know, whoever is setting up the testing, you can decide if you want a hot and humid environment or if you want a cool environment. But what we typically try to do is mirror the conditions that we'll see in the workplace but in that controlled enough fashion so that we're not going to skew the results or have anything that we're going to create like false readings or a false environment that will either give us either better results or worse results. So that, again, is going to be part of that discussion that either internally with your folks that are going to be setting up the test the health and safety folks, the industrial hygienists, along with the consultant that you're working with to help put that together on what you want that picture to look like. But it, typically, for the area, it is going to be controlled to those environmental conditions just to make sure that you're not getting outside parameters or outside influences on any of the results. So, again, that is flexible, that's something that definitely is part of a discussion. But then once you get that into place, that needs to be very tightly controlled and monitored as the test progresses.

Q: Now, is there a target performance level that needs to be determined prior to testing? Do you help folks with that? Do they have something in mind? How does that work?

A: Yeah, it can be either-or. In the pharmaceutical industry, there's a lot of materials that in-house are generated, these exposure limit values the OEGs, the occupational exposure guidelines, of course, OSHA, and the ACGIH have TLVs and PELs and these things. So there are information that's already out there that can be used, or if it's a brand new material and there are no exposure limit information available for that, that's when you need to sit down and make a determination on what would determine a successful test? And where do you want to be with that? And what would you like to see as you move forward with those types of equipment to reduce or potentially eliminate more exposures?

But typically, what we look for is a process control target. We typically look at around 30% of the exposure limit either that TLV, PEL, OEG, whatever it might be, so we want to be on the lower end of whatever that would be for the exposure limit. But again, that's something that if it doesn't exist, if there's not a reference value that you can use, that you really closely work with your health and safety and industrial hygiene folks to make that determination to pick what that value would be. And that value, typically, again, putting on my pharmaceutical hat, it's typically in the microgram per cubic meter value and range that we'll see. But it could be higher or lower than that, of course, depending on the potential hazards that the material might pose to the operators or higher or lower, it really kind of depends on what you're looking to accomplish.

Q: What happens if it fails miserably?

A: You go back to the drawing board, basically. So it's either one of two things, either you go back and you can make adjustments to the testing protocol, okay, to identify, okay, here's where we failed, here's where we need to make changes to the process or to the piece of equipment, and then go back and retest. Or if it's a vendor's piece of equipment, and they've performed the testing and they're supplying that information to you to make a determination on if you want to purchase or not, you send them back to the drawing board and say, "Your equipment is not meeting our exposure guideline or our process control target, you need to do better or we can't consider you for this application." And that's the beauty of it, you really want, particularly if it's a piece of equipment, processes, of course, are a little bit different, because it's a combination of the equipment and the location and the space and how people are interacting with that. But if you're looking at a real specific piece of equipment, let's say a dust collector, that information can be provided to who's ever doing the evaluation, the health and safety folks or whoever might be looking at that, to make a determination to do that risk assessment to say yes or no, is this piece of equipment a good fit for our specific application?

Q: What are some of the next steps after testing, what do they do?

A: So once the testing is completed, of course, you have to culminate the results and get everything together in some type of report to disseminate to whoever might want to take a look at this information. So getting that report together, again, the independent consultant can really help guide what that should look like. You're obviously going to have a mountain of information, you're going to have photographs and videos, and testing results, and all these things that you have to assemble in a digestible format. So putting together that report is really a key part of this to make it again, digestible for whoever might be looking at this information. And what typically happens is there's what we call an executive summary that can be put together. And then if somebody wants to...you know, any individual wants to dig in a little bit deeper, you can have all the raw information and raw data there to present to them if they have specific questions based off of the executive summary.

So, typically, all the results, of course, should be reported as like an activity versus time duration so we're just not looking at one small, little piece. You do want to do that, but overall, typical workplace operations are for eight hours. So you want to look at that time duration if we only have 15 minutes here, do we want to do an extrapolation over 8 hours? Or, okay, we just want to look at that 15-minute duration and see what we have at that specific point in time. You know, all the airborne concentration data needs to be recorded, the method used, do we do just continuous monitoring, or do we do short term? Do we have instantaneous monitoring? And that really drives part of that surrogate testing protocol if...you know, how do you want to record the air sampling and surface sampling? And what equipment do you want to use? And how long are we going to be doing all of this? All the filter sample analysis, obviously, needs to be presented as well. But again, there's going to be a lot of information, so getting a nice executive summary together is really going to help put that into a format that people can understand and make an educated decision on.

A lot of the surface sampling information is used to really identify a lot of potential weak points in the system. There's not really a firm analysis of surface sampling, at least that I'm aware of. So that typically is used as, okay, there shouldn't be any material here but we did a surface sample, a surface swab and we actually found material, okay? Is that a problem? Is that something that we should expect? You know, those kinds of things. So it's really getting that information together and making sure that you've captured all of these little data points that if anybody has a question that you can reference exactly where that was from. And the best part of it is, capturing that much detailed data, that if you do have a failure point or something went wrong, you can identify exactly what happened. And again, as we discussed earlier, go back and make changes to and correct the situation.

Q: How long does this process take?

A: Oh, great question. Flexible, it can vary, really, depending on, okay, we're looking at a piece of equipment, or we're looking at an entire process train. So looking at a piece of equipment, this can be typically done in a standard eight-hour work shift, if you're looking at that. But if you're looking at an entire process train, this can go on for several days, depending on, again, how in-depth you want to get, how many different pieces of equipment and areas are involved in the process train. So it can really vary widely, but just looking at again, taking a dust collector as an example, that typically can be done fairly quickly, within a day or two, all the way through a full process train that you could be conducting that test for a week or longer.

Q: This is pre-emptive, does anybody use surrogate testing after the fact to find out where a failure happened?

A: Yeah, absolutely, absolutely. That's one of the key points of this that if you...you know, once the piece of equipment is in place, and the operators start using it, and there seems to be some issues with that and you're physically seeing maybe some material where it shouldn't be, things like that, then this type of testing can be used to identify those areas. You know, that okay, "Hey, equipment supplier, you said it was going to perform this way. We did our industrial hygiene monitoring, or physically, we are seeing material, it does not appear to us that it is performing at the levels that you said it was." And you can go back and challenge them on this, particularly if you perform what we call a site acceptance test, an SAT. We're actually performing this type of monitoring to verify the supplier's testing results and to hold them, "Hey, this is what we paid for. It's not performing. Either you need to fix it or we want our money back. You need to supply the proper piece of equipment."

So, absolutely, it's a wonderful tool to use after the fact to really make sure...because, again, the containment equipment and isolation equipment can be just crazy expensive. So doing this, obviously, is going to benefit you in the long run. And verifying the performance of the equipment definitely is going to help, not only from a money standpoint...I know we talk a lot about budgets and dollars and cents. But of course, the primary concern here is okay, are our operators and employees being exposed to these materials where they shouldn't be? And then we paid a lot of money for this type of equipment to protect them. And if it's not protecting them, okay, we need to make that situation correct. So yeah, the health and safety of the employee and operators is first and foremost, and if you pay a lot of money for something, you want to make sure it's working properly.

Q: Well, you brought up the M-word, money. Is surrogate testing cost-effective?

A: Yes. And for the reasons that I think we talked and a lot of this actually goes back to the suppliers if you're looking at purchasing this type of equipment, first and foremost, I would ask, "Okay, this is a piece of containment equipment, do you have surrogate testing results that you can provide to us that demonstrates the effectiveness of your systems and what you're using for containment and isolation?" So that's first and foremost. But it does vary if you're doing this yourself as an equipment supplier or a process supplier, of course, it's going to really vary depending on the equipment or system being tested, duration of the testing, number of samples, the location of the testing, and of course, sample analysis and reporting. All of this comes into play with respect to how much this could cost somebody who wants to perform this type of testing. It can, of course, be done in-house, with in-house folks. But to really present surrogate testing results, having an independent company or consultant put their stamp on it and to support those efforts and to even complete that type of testing is really worth it because then you have an independent review of your equipment saying that it is working properly.

There are many companies out there that perform that type of testing. So you can evaluate them and see who's the best fit for what you're trying to test and how you're trying to test but all those things can come into play into the cost. But really looking at the equipment and really doing a thorough analysis and making sure that you're looking at the equipment thoroughly. Worst case scenario, that's typically what we like to see pick a worst-case scenario for what you might be seeing with this type of equipment and do the tests based off of that. But again, it's really up to who's doing the testing and what you want to test and how you want to test and how long you want to test that's really going to have an impact on the cost. But at least, again, just talking, me personally, in my experiences, it definitely is worth the money without a doubt.

Q: And how often should this type of testing be completed? It doesn't seem like you can just do it once and forget about it, especially when equipment gets older.

A: Exactly, exactly. So, of course, it should be repeated if there's, like, any type of significant change in the equipment or process, any modifications that's going to result in a change in how the equipment or processes are being interacted by the operators. You know, or if the functionality of the containment features are going to change. Those are probably the most important things to look at to say, "Okay, we made some significant changes to the equipment, we need to retest to make sure that we're still where we need to be with that." You know, it really ensures that any of the changes that you're making are actually benefiting. Okay, so you might be making some changes, might not affect the containment but maybe now we're over here where it's affecting what we talked about earlier, the functionality. And is that inhibiting now the containment because the operators can't perform that function properly?

So it's really looking at the equipment, have we made a lot of changes? Have we changed the process train? Are we introducing new pieces of equipment into the process train? So do we need to look at it as a whole again? You know, it's really just looking at any impactful change made to either the equipment or processes. You should really probably think about doing another test.

Q: David, is there anything you want to add that maybe we didn't touch on that you think is important?

A: I think, probably, really picking out the surrogate to be used. So with surrogate testing, there's a lot of different materials out there that can be used for a surrogate. Micronized lactose is probably the most common because it's not really a hazardous material. And you can freely handle it unless you have a lactose allergy or something like that. It's a non-hazardous material that you can have milled or micronized to specific particle sizes and all this stuff, but you really don't need to take any extraordinary precautions to handle it or to manipulate it through the equipment or process. But if you need something that has a very low detection limit, we can look at naproxen sodium and some of these other things, other materials out there that have very low detection limit is what we call it. So a way to identify very low quantities of the material that are out there, but some of those materials are what we call active materials, so you do have to take precautions with either respirators or some type of personal protective equipment to handle.

So you really got to look at as we discussed earlier, what is our process control target? What are we targeting? How much of it do we need? Can we be in a shirtsleeve environment? Or, okay, we need to gown up and get our PPE together and all those kinds of things. So it's really an evaluation on what are our goals with this? What type of process control target do we have? And are we going to have to take precautions and do we have a facility that we can manage what we call that active material, or it's we just don't and will not ever be handling that material so we can use lactose or something that allows us to freely manipulate that material without having to worry about it?

For more information, visit: www.camfilapc.com.

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