In this episode of the global Science of Safety Podcast, co-hosts Mark Reggers and Laurie Wells along with guest Dr. Nicole Vars McCullough, Vice President of Application Engineering and Regulatory in 3M’s Personal Safety Division, discuss some fundamental concepts for respiratory protection selection. This is part one of a two-part series on selection.
Tune in to learn more about:
- Airborne contaminants
- Considerations for evaluating exposure
- Occupational exposure limits
- Types of respiratory protection
- And much more.
This global podcast series will hope to not only give you another educational tool that you can use to help increase your knowledge but also something that you can share with others in your organization and with your friends. The goal is to help provide a global perspective and foundation for those of you new to workplace health and safety and personal protective equipment (PPE) while also providing information for more experienced professionals and complex health and safety challenges.
You can listen, subscribe to, and share this podcast through Apple Podcasts, Spotify, Google Podcasts, Stitcher, and most major podcast apps and platforms.
If you have any questions or topic suggestions, you can get in contact with this podcast by contacting your local 3M office or visit our worker health and safety website at 3M.com. If you’d like some assistance in your workplace when it comes to the appropriate selection, use, and maintenance of PPE please contact us today.
Around the world, we aim to help everyone get the job done safely today, tomorrow and in the future.
This year the Personal Safety Division is also celebrating the 50-year anniversary of the first U.S. Government-approved 3M filtering facepiece respirator (a precursor to what is now known as the N95), and the 3M™ E-A-R™ Classic™ Earplug. To all of our customers who have trusted 3M brand PPE between then and now, thank you.
Below is the full transcript of the podcast:
Speaker 1:
The 3M Science of Safety Podcast is a free publication. The information presented in this podcast is general only, should not be relied upon to make specific decisions. Listening to this podcast does not certify proficiency in safety and health. You should always seek the advice of a licensed or certified professional in relation to your specific work or task. Always consult the user instructions for any personal protective equipment you are using and follow local laws and regulations. Information presented is current as of the date of the podcast and requirements can change in the future. 3M owns all rights to the podcast and any reproduction is strictly prohibited without permission.
Mark Reggers:
Welcome back to our previous subscribers and all our new listeners. The Science of Safety Podcast is presented by the 3M Personal Safety Division. This is a podcast that is curious about the science and systems behind workplace health and safety with a focus on personal protective equipment, or PPE used to help keep workers healthy and safe. I’m Mark Reggers, one of your co-hosts and I have the wonderful Laurie Wells with me. We are occupational health and safety professionals who like to ask the questions why, how, and please explain. Whether you’re a safety professional or occupational or industrial hygienist, someone with any level of worker health and safety responsibility in your workplace, a user of PPE or a health and safety nerd, this is the podcast for you. Welcome Laurie, how are you today?
Laurie Wells:
Wow. Thank you so much, Mark. I think it’s tomorrow for you. Isn’t it?
Mark Reggers:
It is. It is. It is Friday here in Australia. So Fridays are always good. Can’t complain with that.
Laurie Wells:
I’m happy to know that tomorrow is coming. I’m sitting here in the US looking at a pile of snow and it’s extremely cold out. And as an audiologist, I want you to know that snow makes a really exceptional sound when it’s below zero.
Mark Reggers:
What is the sound when you walk on the beach in summer in Australia? Is that similar?
Laurie Wells:
I wouldn’t know. You’ll have to make that a topic of another podcast.
Mark Reggers:
I will. I’ll record it next time I go to the beach for you.
Laurie Wells:
Well, Mark, we’re really excited about the topic today and especially our guest speaker. Would you like to introduce to our listeners?
Mark Reggers:
I certainly would. Well today we’re kicking off the first of our two part episodes on respiratory protection selection, and I’m very excited to welcome our guest for this topic, Dr. Nikki Vars McCullough. Welcome. Nikki, how are you?
Nikki Vars McCullough:
Thank you. How are you?
Mark Reggers:
Doing very, very well. Thank you so much for joining us. You are the Vice President of Application Engineering and Regulatory in 3M’s Personal Safety Division, but can you tell us a little bit more about yourself, your background and what do you do with 3M?
Nikki Vars McCullough:
Yes. Thank you. I’m an industrial hygienist by training, background in environmental and occupational health. I’ve been with 3M about 25 years working on various types of personal protective equipment.
Laurie Wells:
Thank you, Nikki, and before we dive into selection of respiratory protection, could you explain to our listeners what a respirator is and how exactly does a respirator differ from a face covering?
Nikki Vars McCullough:
Sure. Respirators are a type of personal protective equipment that is worn by somebody in a workplace to help protect them from breathing in airborne hazards. They’re used by workers in all kinds of different industries, such as heavy manufacturing, pharmaceutical manufacturing, construction, oil, and gas, healthcare and respirators are designed to meet government standards. And these government standards are for the physical performance of the respirator typically. So how much should it filter? How easy should it be to breathe through? How rugged it is?
Laurie Wells:
I imagine that we’re in a global audience now, and I imagine that those regulations might differ in different parts of the world.
Nikki Vars McCullough:
Yeah, many countries or areas of the world have their own standards. They do tend to be fairly similar in many aspects, but again, each country and each area is going to have things that are particular to their population, or particular to their types of work that they do. There are a lot of different approval schemes. You might hear about N95, which is a type of filtering face piece respirator approved in the United States or in FFP2, which is a similar filtering face piece in Europe, or even KN95s, which meet the Chinese standard.
Mark Reggers:
We also have the P2 down here in Australia and New Zealand.
Nikki Vars McCullough:
When we think about face coverings, face coverings or masks, the type that people have been using for COVID, those are not respirators. Those aren’t designed to reduce contaminants that you breathe into your lungs. Face coverings tend to not be regulated in most countries and they’re often loose fitting. So they’re really there to help catch your cough. And so when respiratory protection is needed, when you need to reduce the particles, the gases, the vapors that you’re going to breathe into your nose, mouth, and lungs, you want to make sure that you’re getting a respirator.
Mark Reggers:
So when it comes to workplaces, what do they need to know about selecting a respirator that’s appropriate for them and maybe what they need protection from?
Nikki Vars McCullough:
Great question, Mark. As I mentioned earlier, there are many different types and styles of respirators, and it’s really important that a respirator is selected that is specific to the type of exposures a worker is having. And that might vary from workplace to workplace or even from worker to worker.
Nikki Vars McCullough:
So first you need to know what’s in your air. What are the contaminants? Are they particles? Are they gases and vapors? What chemicals are they? And you need to know how much is in the air. So typically there needs to be some sort of sampling or a risk assessment. One way to do that is to go through a process, exposure assessment process, a risk assessment process. And if you’re not able to do that at your workplace, there often are consultants that are available to help you, or government programs, or even local universities that will have people trained in occupational hygiene or industrial hygiene to be able to help you do that exposure assessment or workplace sampling.
Mark Reggers:
So what are some of those first steps that an occupational or industrial hygienist may use in the workplace to start this process?
Nikki Vars McCullough:
So it really starts with collecting data and information about your workplace and about the types of materials that you’re using in your workplace. You want to get as much information as you can about the different types of chemical and biological agents that might be present. What types of materials are being used and all the workers and their different roles. Then you want to look to see what kind of controls do you have in place already. By assimilating all this data it’s going to help you identify potential health risk to workers and help you prioritize so that you can tackle the most serious exposures first.
Mark Reggers:
Now, with these exposure assessment plans, Nikki, are they a legal requirement in many countries to determine what’s in the air?
Nikki Vars McCullough:
Mark, that’s a great point. There actually are legal requirements in a lot of countries requiring employers to do exposure evaluations for hazards in the workplace. And again, like we talked about before, these regulations are going to vary based on the country you’re in. Sometimes within a country, there are
even different regulations for different industries. For example, ship building or construction. There may also be guidance documents that come out from different regulatory agencies and often we’ll see additional regulations for how the products, the respiratory protection, should be used in the workplace. So it is a complex regulatory framework for the employers. So it’s important that they take the time to really understand it. Or as we talked about, look towards a consultant of some type to help them really understand all of their obligations.
Laurie Wells:
That’s great, Nikki. I’m just thinking, what are these workers protecting themselves from? Can you give us some examples of the types of contaminants that might be present in the air in their workplaces?
Nikki Vars McCullough:
Sure. When we think about the types of contaminants that are present in a workplace with regards to respiratory protection, there’s really three big categories. The first is really a lack of something and that’s a lack of oxygen. So if a worker is in an area, a confined space, or some other area where there may not be enough oxygen, that’s really important to understand because that’s going to take a very particular type of respirator and that’s a very dangerous situation.
Nikki Vars McCullough:
And next we want to look and see, are there contaminants in the air? So what is in the air? And that might be gases or vapors. Things like solvents, things that evaporate from a cleaning process, or maybe vapors that are generated, for example, if you’re doing some spray painting. And the third category is particulates. These are particles that are in the air. They might be dusts, just everyday dust. They might be fumes, mists, fibers or even microorganisms. So when we think about dusts, dusts are formed by applications like drilling, crushing, grinding, sanding, and sweeping, and the smaller these dust particles are the longer they become airborne. And many of these are so small that you can’t see them when you’re looking in the air.
Nikki Vars McCullough:
Mists, mists are typically from spraying. So if you’re doing some spraying and you’ve got little liquid particles, those also can stay in the air for a long time. And those also can be a concern. Now when you think about fumes, some people think about odors, but really fumes are generated during hot work like welding, where we’ve got little metal particles and they evaporate to form a gas, which then really rapidly cools and condenses to form very fine solid particles. And finally, microorganisms. We’ve been talking about this now for two years, SARS, the SARS-CoV-2 virus, which is the virus that causes COVID-19 disease is an example.
Laurie Wells:
But thinking back to the workplace, once you have exposure assessment results, what are the next steps that the occupational hygienist has to take?
Nikki Vars McCullough:
Yeah, the criteria for understanding the exposure results are really determined by the site and they can be very specific to a worker or specific to an operation. So it can be a really complex situation. One consideration is whether any airborne contaminants, the levels exceed any established occupational
exposure limit, or OEL. An occupational exposure limit is the level to which nearly all workers can be exposed day after day for a working lifetime without experiencing adverse health effects.
Nikki Vars McCullough:
Occupational exposure limits can be expressed in a number of ways. Some might be averages over the entire workday, such as an eight hour shift, or some might be averages over short periods of time, or some might be what we call ceiling limits. You can never go over that limit. Occupational exposure limits are set, typically by a local government or by a governmental group. So you will find that the occupational exposure limits in Australia, Mark, might really differ from the ones that we have here in the United States and even be slightly different from the ones published in Europe.
Mark Reggers:
I’ve definitely seen a few of those differences in my time as well. So it is something to really be aware of. Wherever you are in the world, what are your legal requirements?
Laurie Wells:
Certainly a lot to learn and a great guidance, especially for those listeners who may be just starting to learn and go down this journey. So thank you for that good information. Just to go on a bit more, once they know what is in their air and whether those levels are acceptable, then what do they do?
Nikki Vars McCullough:
Once you understand what is in the air, and if the levels are acceptable or not, you can start to put together a control plan and that plan will help you reduce the worker’s exposure to those airborne contaminants. And you really want to follow what we call the hierarchy of controls. Now, the concept of a hierarchy of controls is well established in the field of occupational health and safety.
Nikki Vars McCullough:
There are many types of controls to help reduce exposures and make the workplace safer for workers. Things like eliminating a chemical or process, substituting one dangerous chemical for another safer one, or putting in place engineering controls like ventilation. Personal protective equipment like respiratory protection is also a control. Now personal protective equipment generally falls lower in the hierarchy of controls because they rely on proper selection by the health and safety professional, and proper use by the worker. So for airborne exposures, when engineering and other types of controls are not feasible, or they just aren’t sufficient to get the levels down to a safe level, the next option is respiratory protection.
Mark Reggers:
I’m sure many of our listeners are aware there are many types of respirators, but can you explain what those different types are?
Nikki Vars McCullough:
Sure. It is a big category and there’s a lot of choices. And it’s really important to understand all of the choices when deciding the best way to keep your workers safe and healthy. So if we think about the two most common types, we’ve got air purifying respirators and atmosphere supplying respirators. Air purifying respirators work by removing contaminants from the air by putting the air through a filter or a
chemical cartridge. And these are the types of respirators that are probably most recognizable to people. These are going to be your filtering face piece respirators or your half or full face piece elastomeric respirators. This also includes what we call powered air purifying respirators, or PAPRs.
Nikki Vars McCullough:
The other category is atmosphere supplying respirators, and examples include supplied air airline respirators, which used compressed air from a remote source, such as a breathing air compressor, but also SCBAs, which are self-contained breathing apparatus. Those include their own air supply. Those are the types of units you see firefighters using commonly.
Mark Reggers:
It certainly could be quite overwhelming for many workplaces looking at all those different types of respirators that you’ve kind of given an overview of, but where does a workplace start to determine which respirators select for them?
Nikki Vars McCullough:
So if we think about respirators, as we’ve been talking, respirators are designed to help reduce, but they don’t eliminate all exposures to airborne hazards. So a concept that we’re only going to touch a little bit on today is the concept of an assigned protection factor. In many countries, respirators or classes of respirators are given an assigned protection factor, which is also called an APF. The APF is the expected ability of the respirator to reduce the exposure when used according to an effective respiratory protection program.
Nikki Vars McCullough:
For example, if you have a type of respirator that has an assigned protection factor or APF of 10, that means the respirator, when used properly, is going to reduce the exposure by a factor of 10 or 90%. And again, these APFs are assuming that the respirator is used properly, the worker has been trained and the respirator’s being maintained. So that’s really important to think about.
Nikki Vars McCullough:
When you’re in your workplace and you’ve just looked at your exposure assessment, you’re thinking about your controls. You want to determine what level of APF your workplace needs and to do that you want to divide the concentration or the exposure level in your workplace by the occupational exposure limit. It’s a simple ratio and we refer to that ratio as the hazard ratio.
Nikki Vars McCullough:
Let me give you an example. If your exposure level from your place exposure assessment shows a concentration of 500 parts per million and the occupational exposure limit for that contaminant is 50 parts per million, you would divide 500 by 50 letting you know that you need a respirator that has at least an assigned protection factor of 10. So once you know what your minimum assigned protection factor is, then you can look at the types of respirators that have that assigned protection factor.
Nikki Vars McCullough:
Now, again, like we talked about with exposure limits, different countries have assigned different assigned protection factors for the same respirator. So as Mark mentioned earlier, it’s really important
to understand, okay, where is your workplace? Where is your worker? What are the local or national occupational exposure limits? And then how are the respirators class of in this country or this area of the world and what are their assigned protection factors?
Laurie Wells:
Wow, Nikki, you made it sound easy. There’s so much to learn and we’re lucky enough that we had you here today, and that we have the opportunity to have you back again to expand our discussion and learn more in the next part of this two part series on respiratory protection selection. We’ll dive a little deeper next time into the different types and the styles of respirators, and really look into some considerations for selecting appropriately and including the concepts that are so important, like the fit and the PPE compatibility. So thank you. Thank you Nikki, for taking time to be with us today and for providing these great explanations,
Nikki Vars McCullough:
Thanks to you, Laurie, and Mark for having me. This is really a very relevant topic right now. Respiratory protection is being talked about on the news and by people more than ever before. So helping employers understand how to keep their workers safe is really an important topic right now. And thank you for having me.
Mark Reggers:
Absolutely Nikki. Well, thanks for listening everyone. You can listen, subscribe to and share this podcast through Apple Podcasts, Spotify, Google Podcasts, or wherever you get your podcast from. If you’d like some assistance in your workplace when it comes to the appropriate selection use and maintenance of PPE and of course, including respiratory protection equipment, you can get in contact with your local 3M office or visit our website and search for your country. Around the world we aim to help everyone get the job done safely today, tomorrow, and in the future. Thanks for listening and have a safe day.
Laurie Wells:
Hey, stay safe out there Mark.
Mark Reggers:
Stay healthy, Laurie. Thanks everyone. Bye.
Laurie Wells:
Bye-bye.