What is an airborne molecular contaminant

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Trent Thiel  
If you're stuck inside of a building, a lot of times you don't have proper molecular filtration or good ventilation. You know, when you're tired throughout the day, it's not because you were streaming your Netflix show on repeat. A lot of times it can be the chemicals that are inside your space.

Dusty Rhodes  
Hello there and welcome to Let's Talk Clean Air, our regular look at how clean air can affect the quality process for you and the workplace. On this episode, we're finding out about odors, gases and toxins in the air and how to deal with them. My name is Dusty Rhodes joining me to explain more about this is Trent Thiele from Camfil, USA. Trent is an industry expert and educated in molecular filtration. And with over 150 million registered chemicals in the world that is quite an area that he covered. So let's get in and find out more about molecular filtration with Trent. Trent, you're very passionate about this whole area. Tell me why.

Trent Thiel  
Yeah, so it's one of those things that I've been with Camfil for about eight years. before I came on with them, I was more involved in the industrial process gases. Um, you know, and that's kind of an area that people understand there's industrial gases that are there, and you don't really understand about how all of those gases can actually impact the people, the environment and other processes and equipment around them. Right. So it was one of those things that I didn't really understand until I really got into the business. And then once you understand about how this impacts not only you know, when you get outside of the industrial aspect of it, we're talking about our families, our children that are in schools, that are in office buildings, things of that nature, and really understanding and being able to educate about how these, we're all familiar with particulate matter, right, we all have particulate filters in our home, we understand particulate matter, it's one of those things that for, for all intents and purposes, you can touch it, you can you can see it right. With molecular contaminants, it's kind of out of sight, out of mind. And so people don't really pay attention to it until it's a problem. And so, for me, as an educator, it's really, it's really important to, to make sure that other people have awareness around that and understand how it really does impact our daily lives. And so it's something that I have become passionate about. And, and it's important, you know, to be passionate about what you do. Because in that way you can learn more every day. I mean, as you mentioned, there's over 150 million registered chemicals will actually now dusty that was that was probably from one of my old my old excerpts that you took from somewhere, but it's actually over 252 million registered chemicals now. Um, yeah. And when I first started with Camfil, there was actually only 73 million registered chemicals. So in eight years, that numbers is more than it's more than tripled. So it's pretty incredible.

Dusty Rhodes  
are a lot of these chemicals. I mean, they all particulates, are they all molecular or Is it a combination?

Trent Thiel  
Yeah. So it's it can't mean you know, it could be a combination, you have a service called chemical abstract services. So every chemical out there has a cast number, right? When you look at the MSDS, or I guess the safety data sheet now as what we call them, you can see a case number associated with that. And some of them have other CAS numbers associated with them as well, because different chemicals can make up a combination or new a new chemical compound, right? So a lot of them are derivations of each other. There are minerals, different polymers, you know, even some salts and things like that, you know, alloys, and a lot of those are molecular contaminants because it'd be considered particulate. But for the most part, you know, there's, there are, you know, there's over 252 million registered CAS numbers, I should say out there.

Dusty Rhodes  
The first official question I want to ask you was what is an airborne molecular contamination?

Trent Thiel  
Yeah. So what you would have first and foremost to an airborne molecular contaminant you have, we're talking about airborne contaminants in general, right? So as I mentioned, you have particulate matter, and then you'd have molecular contaminants. So what I always like to start with, with things that people can wrap their minds around again, the particulate matter, right, so you got according to, you know, the ISO, that you know, not to throw numbers around, but ISO 16 890, you've got four different particulate categories. From sizes or particularly, you have coarse particulates, which would be those particulates from point three to 10 microns, you would have Pm 10, which would be from point three to 10 microns. Then you'd have PM 2.5, which is really what we care about from entering our homes and office buildings and schools, which is point three to 2.5 microns, and then you have pm one, which is point three to one microns. And those are the things we care about in healthcare environments and surgical suites, right when somebody is being operated on, you don't want to have any type of contaminant that could potentially get into that space. And, and so and then once you get past that is where HEPA filtration, a true high efficiency, particulate arrestance would come into play, which would be where you get efficiencies of point three-micron particulate and so on. And so when you're going into airborne molecular contaminant, you're talking about an individual molecule that is actually could be 100 to 1000 times smaller than those point three micron particulates removed with the EPA filter.

Dusty Rhodes  
Okay, so all the numbers that you've been describing so far, you're essentially saying that they're getting smaller and smaller auto present. So you're talking about stuff that, you know, we're worried about the BM one is, that's what we worry about when people are lying could open on an operating theater we make to need to make sure but what you're concerned with, which is molecular is 1000 times smaller. Yeah, wow, that's kind of mind-blowing? What are the most common contaminants then that we see?

Trent Thiel  
So a lot of questions you're gonna ask me, I'm going to say it depends, will be but now how I first will answer you? Because it does, right. It depends on where you are. Because if I'm at let's say I'm at a petrochemical refinery, right, versus if I'm at your daughter's school, because the contaminants I care about are going to be completely different. Right? Okay, so. So again, what I always like to do is I like to start with, with things that majority of your listeners would probably want would probably gravitate to, which would be what we would consider general indoor air quality. Right? IAQ we hear that term a lot, stands for indoor air quality. And so when speaking, for general IAQ, really, what you care about is you have to look at your indoor environment and your external environment. So from the external environment, what you'd really care about are things, there's three primary contaminants that I would say from, from a chemical standpoint you'd be concerned about. The first would be ozone. So ground-level ozone, ground level, ozone is generated from UV light, essentially reacting with exhaust from industrial processes and from vehicles. So when we talk about clean air vehicles and things like that, the reason we push that so hard is because without a lot of the, emissions from these vehicles, you wouldn't be getting that ground-level ozone, because the UV wouldn't be reacting with any of those chemicals. And the same thing with factories right as CO2. So sulfur dioxide that would be coming out of that would be coming out of factories also can react with UV light and generate ground-level ozone. So when you have things like, like, you know, and from the cars, you have things like B Tex, you might have heard that acronym before stands for benzene, toluene, ethyl benzene, xylene, which are all which are, you know, again, those are the kinds of chemicals that we've looked at from TV of C total voc standpoint, from the exhaust of these vehicles, that's kind of what we look at until you mean is used as a surrogate gas many times for simulating the impact that vehicle exhaust can have on an environment. So the three things you should be concerned about, again, all those chemicals I just mentioned there, you can drum it down to three things, which would be ozone, nitrogen dioxide, and sulfur dioxide. Nitrogen dioxide is primarily going to come from diesel fumes. I should say it's oxides of nitrogen. So you get some, you know, nitrous oxide, things like that as well. But or nitric oxide, but um, you But yeah, but main ones are going to be nitrogen dioxide, and otoo. Sulfur dioxide known as SF two, and then ozone, which is known as Oh, three. And that's from outside air. Now, I

Dusty Rhodes  
Now, I know, you're going to say it depends. Yeah, but what kind of effects do those nasty things have on us? Little human beings? Sure.

Trent Thiel  
Yeah. So you've got you know, the main thing that people identify when they say, Oh, I need to, I need a molecular filter. Most people think, you know, most people say I need a carbon filter. But we can talk about the difference between a carbon filter and a molecular filter here in a couple of minutes. But the main, the main contaminant, or the main reason people think they need molecular filtration would be odors, you know, smells, but the primary reason people need molecular filtration and may not realize it is for irritants. So ozone and nitrogen dioxide, for example, ozone can have extremely detrimental effects on your lungs. You know, there was a lot of several years ago, there's a lot of ozone generators inside of inside of buildings inside of homes. And then we found that yes, ozone is a very good oxidizer, um, but it also will turn your lungs to leather. And so it can actually start impacting your lung health and can cause for those that have respiratory issues, you can have further lung damage. So it's really just protecting your pulmonary tract. Nitrogen dioxide, while it also can impact your lungs can also impact your brain. You know there's it can make you lethargic so many times, you know, it can make you can make you lose focus. So, if you're stuck inside of the building, a lot of times you don't have proper molecular filtration or better or good ventilation. You know, when you're tired throughout the day, it's not it's not because you were streaming your Netflix show, you know on repeat for eight hours that night, you know, a lot of times it can be the chemicals that are inside your space. It kind of leads me back to what I was going to talk about the internal contaminants. We talked about 252 million registered chemicals in the world. And you've got, you know, inside of the space, you can have things like cleaning supplies, you can have construction materials, which would have adhesives in different aldehydes and glues that are off gas, you know, all the time, even clothing, right? The different dyes and pigments and food, one of the biggest contributors, right, so the inside your indoor environment is always is dynamic and changing constantly, depending on what's being brought in what's being what's being taken out. And so, you know, to say to say, what are the most common contaminants from inside, I wouldn't be able to even, you know, even venture a guess, you know, I would say it depends on the types of foods you're eating depends on the material construction materials that have been used inside of your space, the cleaning supplies. So, but that's so I would say irritants as far as its impact on human beings. irritants are the number one reason people should be putting molecular filtration in, but odors are the number one reason people think they need molecular filtration, because it's really the only identifier that we have. So

Dusty Rhodes  
we've got the smell. You've got irritants which can irritate you toxins, which are just poisonous. Yeah, sure. I'm sure many of these things as well can also affect the equipment's that could be in a in a facility. Yeah, you come across them. Yeah. So there are four.

Trent Thiel  
Yeah, yeah. So there are four. And I should I should have mentioned toxic gases as well, you know, but I was, I was still thinking about the general IQ. And typically, you're not going to find toxic gases in general IQ, many times it's going to be, you know, that's going to be more closely related with and military operations, they things of that nature, right, where that's our nuclear applications where, you know, where you've got different types of radioisotopes you're trying to remove, or I guess that, you could, but in any event, but yeah, the fourth category would be corrosion control. So you have four reasons people would need molecular filtration, odors, irritants, toxic gases, and corrosion control for the protection of processes and equipment. And that's really why a petrochemical facility would have would have it pulp and paper facility, you know, metal refining, for precious metals, microelectronics, is probably the one of the biggest ones that's out there that that has very specific needs for the different types of, of corrosive chemicals, that would that would impact there, that would impact their, their processes and, and product.

Dusty Rhodes  
Now, I'm not an expert in the area, which is why we have you, when it comes to particulates I can understand how a filter is able to trap these things and to stop it coming in through the facility. But if molecular is so small, how do you how do you control that with a filter?

Trent Thiel  
Yeah, that's a good question. Um, I don't know. No, I'm kidding. so there are two types of mechanisms that you would use to remove a molecular contaminant, which is also important to understand why you need molecular contamination control. So it would be you know, what is the purpose, right? Is it protection of humans? What are you protecting those humans from? is a protection of a process or equipment? What are you trying to protect them from? So when you look at all these different chemicals that are out there, dusty, what you have are, these chemicals have a molecular weight, they've got a vapor pressure, and they've got a boiling point. So the lower the molecular weight, and the lower the boiling point, and the higher the vapor pressure makes it tougher to capture. Right? So those are really fast molecules, right? They're very, you know, they're, they're very volatile. There's other ones that are bigger, slower, right? If you think of the molecule being slow, and so that they would be captured by those ones. 99% of the registered chemicals out there are going to be best removed with physical adsorption. So you have chemical absorption and physical adsorption. Physical absorption is the most common when people say, Oh, I need a carbon filter, they're most likely talking about physical absorption. So the way that it works is that if you can imagine you've got kind of a pegboard sitting on your desk there. And all those little peg holes are in there filtration in the molecular filtration industry we call active sites. And so these active sites have intermolecular forces. And it's the same way kind of a spider climbs up the wall. So every single solid service on planet Earth has molecular has intermolecular forces, right? So the molecules that are on the end of a spider's feet, or legs, if you will, are weak enough to be attracted by those intermolecular forces. But the spider is strong enough to break those weak bonds and move to wherever we need to. These molecules aren't looking to break those bonds per se. So what happens is that you have static pressure from a filter right? So you're forcing that air in through a filter, and then that those contaminants are being pushed through this porous substrate. Whether it be a coal type carbon, or other organic material, like coconut shell, even and wood based carbons, so they're what they're doing is being forced into this activated carbon to then react and be held on the surface of each one of those active sites. And so there's a finite number of active sites that right, which is why you can have predictive lifetimes of these of these carbon filters. And so that's the first one would be physical adsorption. The second one would be for the capture of things like ammonia, it would be for the capture of hydrogen sulfide, it would be you know, things and things like that, that would be again, have a lower boiling point, a lower a lower molecular weight, and or a higher vapor pressure, and you have to chemically react with those. So those active sites, then instead of, instead of being open and ready to receive these chemical contaminants, for all intents and purposes, they're actually, you know, just, it's a little more a little more complicated than this, but they're filled back to those, those active sites are filled with a chemical that will react with that target chemical you're trying to address. So if you have a strong acid, you'd put a strong base on the, on the surface of that media to neutralize it. Right. So if you have hydrogen sulfide, you would put something like potassium hydroxide on there to be able to essentially render it neutralized.

Dusty Rhodes  
So what you're saying is you've got a carbon filter or some kind of a physical surface, and it's what you coat the filter with, or the liquid, shall I say that says it's in the show the filter, and that's what's stopping the really tiny molecular contaminants? Absolutely,

Trent Thiel  
yeah. And there's different you know, there's different types of when you talk about chemical substrates, then you can use like activated alumina Titan type substrate, and what we call it is actually, it's, it's an, whether it's activated carbon, or activated alumina or different types of different types of base substrates. We call that in impregnating the media. And so what actually happens is that you like so, for example, because what you want to do is you want to get the most complete impregnation of that media so that you can because this, this media is extremely porous, right? So if the molecule progresses through, you know, it goes past, okay, that active sites taken up that active sites taken up as a progressive through the filter, you want to make sure that you have as much time for it to react with those different active sites, so that you can have a higher removal efficiency. You know, again, I'm really simplifying a lot of this, but, but that's kind of you know, when you think about it, just think about that pegboard pegboards, either empty and ready to receive heavy, you know, slow molecules, or it's filled with a chemical to react with the targeted chemical that's tough to capture.

Dusty Rhodes  
For some reason, I get the feeling that the molecular are more complicated or don't last as long. How do they compare with carbon filters? How often would you have to change them? I know, I know, that depends. But give me give me an idea.

Trent Thiel  
Yeah, no, and actually, so yeah, I thought you're gonna save to particulate filters I'm liking the filter most likely will not last as long as a particular okay, but, you know, to, say, a carbon filter versus so


I guess.

Trent Thiel  
How do I answer that? Um, there's, it does depend, right. So let's, so you have, let's say that many times, you're not going to need I need a filter just for hydrogen sulfide, you may need a filter that's also going to address ozone, right? You also may you may need a filter that's going to address Tallinn or benzene or, you know, again, one way or the other 99% of those 252 million chemicals out there. Right. And so that's what you need physical absorption and chemical absorption, the same filter. So is that what you're asking to physical absorptive media and chemical absorptive media? Do they do they expire at different times? Is that what you're asking?

Dusty Rhodes  
That's that kind of Yes.

Trent Thiel  
Okay. Okay. And yeah, and they and they would. And so unfortunately, most times when people say hey, I, you know, I want to address as much of this stuff as possible coming in from outside air, okay, fine. And what they'll do is they'll take a chemical-impregnated media, and they'll take a physical absorptive media like carbon and blend it together in one unit. And while that sounds great, when it passes through and in a single pass from outside air, you only have one chance to capture it. So you've dedicated 50% of your filter to immediate that's only going to react with less than 1% of those outside air contaminants. Right? So what's the solution? Yes, the solution the best solution and again, I'm not saying I have nothing problem, I have no problem with blending the media is an advantage would be it takes up less space, less initial cost. But the best solution would be take a physical absorptive media and a chemical absorptive media and you'd layer them right so you'd have a stage of physical absorptive media stage of chemical absorptive media. And then and then that way you can test them individually and see what the remaining lifetime is of each of those. You're not wasting any of that any of that means you're not wasting your money. So from an initial cost, yeah, blending them together in a single stage to address, you know, whatever you want to remove. Sounds like a good idea, right? But from a total cost of ownership perspective, it's always better to have two stages, if you can afford the space.

Dusty Rhodes  
Going from tiny molecular scale, sure, to these filters, how big an operation? Can they work in? What kind of scale? Can the filter solutions be deployed? Sure, sure.

Trent Thiel  
Yeah, so the way that they're, it could be anything from like, let's say, again, let's start with, with things that people can understand. Right, let's start with something that we can actually wrap our minds around start with schools offices, so you use what we call an embedded media filter. So it can be it can look just like a filter that's actually in your that's in your HVC unit at home, right, just something you'd buy at the hardware store. And what's actually what there's actually is inside of that is embedded molecular media, most cases activated carbon, that would be able to provide you Okay, removal efficiency for like concentrations of gases in your home. So then we also have more advanced embedded media filters for the healthcare industry, right, that would be a combination of pm of pm one, filtration, and embedded molecular media to be able to interest things like ozone at over 90% removal efficiency. So that's kind of a compact one that you that you could put in just for general HVC commercial or application, then you move into what we would consider a, you know, light process, for example, to heavy industrial, like process could be something like in vitro fertilization, where you would have, where you'd want to have more targeted, you'd want to have more targeted molecular contamination control. And so you would take a shell, for example, you know, could look, it could be a box, it could be a cylinder, it could be different panel, it could be different configurations, depending on the space that you have, you know, in your budget, and the removal efficiencies that you want to maintain, and you fill those different casings with particular molecular media's to be able to address the contaminants that you want to address. So, you know, this could be for general manufacturing labs, for example, have very specific, you know, you'd be looking at very, you know, a couple different types of gases that they'd want to remove. And then, you know, even corrosion control, for example, like a refinery, they have these, these motor control centers, right, the control room of the brains of the entire operation of a refinery, they want to protect that, from the printed circuit boards and the computers getting corroded. And so, you would have, you know, again, you'd have a more industrial solution, so you can have something that would, that could be several 1000 pounds of media. So I would say from, you know, progressing and what we just talked about, think about it in, in, I should probably speak in kilograms as well. But so think about it in terms of five, five kilograms, okay, you know, for the small scale, you know, in a, you know, one single opens at 10 pounds. Yeah, that 10 pounds, you have to lever to let's call it 50 kg for, for light process solution, you know, could be, you know, in the, in the, in the hundreds of, you know, in the hundreds of pounds, and then finally, you'd have 500 kg or more for 1000s of pounds, wow, media in a solution. So big box that you would put Next, let's say you got to, you know, you've got like, polyurethane foam manufacturer, right, you know, foam mattresses, for example, they put out a lot of a lot of contaminants. And so for protecting the environment, and those people around them, they have to put large industrial scrubbers out there to be able to have high removal efficiencies for a long period of time.

Dusty Rhodes  
So it can be done on a big scale. How do you know if they're if the solution is working?

Trent Thiel  
Sure, good question. You can do air sampling, obviously, you know, upstream and or downstream, that's gonna Yeah, and there's, there's real time monitors for that that are out there. You can also we have canceled ourselves have even before you purchase a solution, there's the ability to be able to do sit, use simulation software, to be able to look at different absorption theories, and really look at the concentrations of the gases and understand how they you know, and the, the contact time, meaning how long the look at the velocity of the air passing through that design you've made, whether it be through hundreds of pounds of media, 1000s of pounds of media, you know how long it's going to be in contact to be able to see what the initial lifetime would be, but then nothing's as good as taking a sample of your media, sending it back to the manufacturer, which you purchased it from, and letting them sample the media to be able to see what the remaining life is. So you'll be witnessing See what they're doing is seeing how many more how many of those peg holes do you have left that are open is what you're looking for. So you would have to do that with media sampling. And there's different types of, obviously with the different types of media. And there's different types of media sampling that has to take place.

Dusty Rhodes  
And that gives you much better idea then of when you should change the filters on a percent. Trent, you make all of this sound absolutely amazing. And you've explained it so well, and I understand it. And thank you so very much for joining us on the podcast and today. If you'd like to find out more about this, just follow the links in the show notes. You find them in the description of the podcast on your phone, or whichever device you're listening to us on. They include links and contact details for Trent and anything else that you might need to get more information. Our podcast today was produced by Camfil, a world leader in the development of production of air filters and clean air solutions. To stay up to date on how clean air can affect the quality process for you and your workplace. do click follow so that you get our next podcast automatically on your phone or wherever you're listening to us. Until next time from a self destructs thank you so much for listening and take care