Welcome back to the Science of Safety Podcast. In this episode, co-hosts Mark Reggers and Laurie Wells along with their guest, Jessica Tredinnick the 3M Global Standards Development Manager from PSD, discuss the importance of fit for tight fitting respirators. Tune in to learn more about:
- What is the science of fit?
- What is a fit test?
- Fit testing methodologies
- How often is fit testing required to be conducted?
- Fit tester competencies
- The 3M approach to respirator design
The first global season of 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.
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 visiting 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.
This year we are celebrating the 50-year anniversary of the first NIOSH-approved 3M filtering facepiece respirator, and the 3M E-A-R Classic Ear Plug. To all of our customers who have trusted 3M brand PPE between then and now, thank you.
Around the world, we aim to help everyone get the job done safely today, tomorrow and in the future.
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 a 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 production is strictly prohibited without permission.
Mark Reggers:
Welcome back to all our previous subscribers and new listeners. The science of safety podcasts are 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 with the fantastic 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, 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. Then this is the podcast for you. Hey Laurie, how have you been?
Laurie Wells:
I’ve been great, Mark. It seems like forever, since we talked.
Mark Reggers:
Does seem like a while, but I’m going to test your memory here. Do you remember way back to our first intro episode when we were learning about each other? Do you remember one of the things that I am incredibly passionate about?
Laurie Wells:
Oh, of course I do. It’s basketball.
Mark Reggers:
Oh, well true. true. That is one of the things, but from a professional point of view, what’s something else I am that passionate about?
Laurie Wells:
That’s an easy one too, because we have the same passion professionally, which is about fit testing and only differences. Yours is about respirators and mine is about hearing protection. So although they’re different hazards, we’re focused on the concept of fit and how it applies to personal protective equipment or PPE is an incredibly important one.
Mark Reggers:
Look, I’m incredibly excited today that we are going to be talking about respiratory protection and the science of fit with our fantastic guests, Jessica Tredinnick welcome, Jessica.
Jessica Tredinnick:
Thank you, Mark. It is an absolute pleasure to be here with both of you today to chat about a topic. That’s one of my favorites too, which is respirator fit.
Laurie Wells:
Well. Jessica is the Global Standards Development Manager for 3M Personal Safety Division, which is a really unique and important role. So Jessica, could you please tell us a little bit more about what it is you do at 3M and your professional background?
Jessica Tredinnick:
Sure. I manage PSD’s team of global standards development and regulatory affairs specialists. So, it’s our job to be familiar with standards that apply to personal protective equipment, either their performance or their selection and use all over the world and we track both standards that already exist and also standards that are being revised. And in some cases, standards that are being developed better new standards. I have a background in communications and also industrial hygiene and previous to my current role at 3M, I’ve held positions in occupational health and safety operations organization within 3M, and also our marketing organization and product development and technical support for respiratory protection. So I’ve done a little bit of a lot of things here at 3M.
Laurie Wells:
Wow. Well, we’re really lucky to have you here with us today and I know you have, an inordinate amount of experience and, but I’m going to just ask you right from the start and start from the basics. What is the science of fit when it comes to respiratory protection?
Jessica Tredinnick:
Yeah. Well, thanks Laurie. And like you said, fit is so important when it comes to PPE. And just like with hearing protection, the same is true for respiratory protection. There’s no single respirator style size or brand that is going to fit every single face. And if certain respirators don’t fit properly, then an employer, can’t be sure that a worker is adequately protected. A respirator that isn’t able to seal effectively to the wearer’s face can allow contaminated air to pass around the respirator instead of going through the respirator filter or cartridge. And that’s not what we want to see happen. So the science of fit for respiratory protection is all the elements that go into the respirator and the wearer being able to reliably achieve an adequate fit and by fit, we mean an effective seal that forces the air to go through the cartridge or filter.
Mark Reggers:
You’ve kind of hinted. There are many factors which can impact or reduce this, you know, this likelihood of achieving that seal and that fit. And therefore, that protection every single day, whenever that product is being worn from your very varied experience, what are some of these key things that workplaces and workers should be aware of when it comes to things, affecting fit in respiratory protection? Jessica Tredinnick: Page 3 of 8 There are a number of key considerations that come to mind that we could talk about here today. So anything that might get between the sealing surface of the respirator and the wearer’s face is something to think about. And one of those things, which is an ongoing challenge for many workplaces is facial hair. I do a lot of speaking about respirator fit testing, and this is one of the issues that comes up a ton. So facial hair, we know is one of the biggest challenges for a lot of respirator program managers, wearers of tight-fitting respirators need to be free of facial hair every day when they wear that respirator. And when we say tight fitting respirator, uh, we mean respirator types that rely on the seal with the face in order to direct the inhaled air through the filter. another factor that comes into play sometimes could be facial piercings.
Jessica Tredinnick:
If they interfere with the seal or head garments that might interfere with the seal, all of those things can challenge a respirator’s ability to form that effective seal with the wearer’s face. Another common factor is weight change or dental work. If it’s big enough dental work that can change the shape of a person’s face and can then also impact how their respirator seals to the face. But then another element that sometimes we overlook is the training and education and the ability of the workers to fit the respirator correctly and effectively, because that’s also just as important as the dimensions of their face, and then finally taking care of those respirators. So, the way that the respirators are designed, they’re designed to fit a population of workers, and it’s important to care for those respirators and maintain them and clean them so that they can continue to function the way that they’re designed to function.
Jessica Tredinnick:
And another issue that can affect, respirator fit is compatibility PPE compatibility. And by that, I mean, if somebody has to wear multiple types of PPE on their head, it’s important that each of those pieces of PPE is able to do what it needs to do and be worn what it, where it is supposed to be worn on the head. And the most common compatibility challenge that we see with respirators is when respirators need to be worn with safety glasses or any other eyewear, really. and that’s particularly a challenge for half face piece respirators because those half face pieces and eyewear often need to occupy the same space on a wearer’s face.
Laurie Wells:
Well, many things to think about for sure. And, you know, with fit being such a critical element to achieving appropriate protection, how does a workplace or an employer, or even an individual know what respirator fits them? Or maybe I should ask more importantly, what respirator doesn’t fit.
Jessica Tredinnick:
Laurie, those are important questions. How does a workplace or an individual wearer know whether the specific respirator model that is issued is going to fit, or if it even can fit a workplace of course, needs to know that information before a worker is in a contaminated environment. And this is where a respirator fit test comes into play, a respirator fit test is a validated method for confirming that a tight fitting face piece matches the person’s facial features well enough to form that effective seal on the wear’s face fit testing can also help identify respirator models that are unsuitable for particular worker populations, which as Laurie indicated is just as important as individual fit
Mark Reggers:
Something. I always try and highlight as well as that a fit test confirms that a fit can be achieved, which yes is very important, but it still relies on that where it to fit it correctly each and every time it’s, it’s worn on the job. So we need to reinforce that the right behavior is happening when it matters most.
Jessica Tredinnick:
Absolutely Mark that’s totally correct. You could fit test me today, but if I don’t wear the respirator correctly tomorrow, or the next day, I may not receive that expected level of protection that I need from the respirator. This is where the process of fit testing and the information that’s provided to the wearer around the why of fit, testing, and understanding the impact that the seal has on achieving protection has a big influence on worker behavior change and their understanding on the job.
Laurie Wells:
Absolutely. Just similar to hearing protector fit testing education is really key and an important factor when thinking about any kind of protective program. So if we think back, we spoke in a previous episode about respirators in the many different types that there are. So, I’m curious, Jess, are there different ways to fit test these different types of respirators?
Jessica Tredinnick:
Yes, Laurie, there are a number of different validated fit testing methods, and they can be broken down broadly into two categories. There’s qualitative fit testing and quantitative fit testing. And I’ll talk a little bit about each of those categories. So first qualitative fit testing, those are pass, fail, fit test methods that rely on the subject’s sensory response to detect a challenge agent in order to determine whether the fit is adequate for qualitative methods, you have the aerosol qualitative fit test. That’s one of them. That’s often called an aerosol taste test in many countries, and there’s also the vapor qualitative fit test with isoamyl acetate, or some people call it banana oil. And then finally there’s the irritant smoke method. And for that method it’s stannic chloride is the compound that is sort of the active ingredient in that challenge agent of all of these methods, the aerosol taste test is the most commonly used qualitative methods. And all of them, like I mentioned, uses what we call a challenge agent. So that’s something that the respirator fit test subject needs to either taste or smell to confirm whether an adequate seal has been achieved with the respirator.
Mark Reggers:
So that’s qualitative. what about, I’ve heard of quantitative, can you expand a bit more about that method if that’s okay?
Jessica Tredinnick:
Yeah, totally. So a quantitative fit method is again, a pass or fail method, but this one uses an instrument to quantify, to actually measure the amount of face leakage into the respirator in order to assess the adequacy of the fit. So instead of relying on the wearer to, communicate to the fit tester what they’re experiencing with quantitative fit test methods, it’s actually an instrument that’s measuring the quality of the fit.
Laurie Wells:
Well with all these different types you can imagine I’m going to ask you this question. So which one is the best one or is there one that’s recommended over all these others?
Jessica Tredinnick:
Great question. All of the methods that I just described have pros and cons and typically standards generally don’t recommend one over the other, although there are some exceptions to that. So it’s important to understand your local regulations and what they require, but this is why it’s important that workplaces are informed of all of the pros and cons when they’re deciding which fit test method to use. We probably don’t have time to get into all the nuances of each of the methods right now, but that is definitely where 3M can help a workplace work through all the different methods and choose the one that’s best for them. At the end of the day, whichever method is selected, the competent fit tester has to follow the procedure to have reliability in the fit test outcome, whether it’s a pass or a fail.
Laurie Wells:
All right, now let’s turn our attention to a different topic. Just when do one of these fit tests have to be done? Can you talk about the requirements or if one time enough, one and done, or do you have to repeat this every so often?
Jessica Tredinnick:
Great question. This is another common question that we get from workplaces it’s required before the very first use of a tight fitting respirator for somebody to be fit tested. And then it’s also required for the wearer to be fit tested, anytime a different size style model or make is going to be used. And then a fit test needs to be repeated if there’s any change to that person that might impact the quality of the seal, that’s able to be achieved with the respirator. And so those changes might be a change in body weight, or a change to the face in the sealing area. So we already talked about how, changes to the dentistry could change the size or the shape of the face enough that it could impact fit. But also, if there’s any significant facial scarring, that’s another situation where the fit test might need to be repeated.
Jessica Tredinnick:
So really in summary, whenever there’s a change to the face that might impact fit, the fit test should be repeated. And then regarding other circumstances where fit testing might need to be repeated for the wearer, if there are no changes like the ones we just mentioned, then it’ll just depend on the local regulations or standard recommendations. So in the United States, for example, which is where I’m located at the moment, it is a legal requirement for employers to perform annual fit testing of workers ]who are required to wear tight fitting respirators . In a lot of other countries there are standards that require fit testing to be done annually, but that’s not true everywhere. So again, it’s important to be familiar with your local regulations.
Mark Reggers:
Now, a common question I get asked when I’m talking about respiratory fit testing and the importance which we are kind of discussing today is, is fit testing a legal requirement, or do they really have to do it? Cause it does take time and resources and effort and, and people off the job to do this important thing. How would you typically respond to this type of question when you get posed?
Jessica Tredinnick:
Yeah, that is another common question that we get worldwide really. And in a lot of countries, it is a legal requirement to conduct fit testing, whenever tight fitting respirators are being used, and so that’s true. For example, again, in the United States in many other countries, workplaces have a legal duty of care obligations and PPE regulations, to ensure that PPE is suitable, that it’s a proper sized fit that it’s reasonably comfortable. And then in those situations, fit testing is an accepted way to meet those legal obligations. Fit testing is a mandatory part of any respiratory protection program as outlined by many countries, respiratory protection standards across the globe and not to belabor the point, but fit is of course a crucial factor to whether protection can and is likely to be achieved for tight fitting respirators. And so as a manufacturer, we can test performance characteristics, according to manufacturer standards like filter performance and breathing resistance and etcetera, but we can’t test how the respirator might fit on every person’s face who might wear one of our respirators and no manufacturer can do that really. And so that’s just all to say that fit testing is absolutely an essential part of helping to ensure that the respirator is able to provide that level of protection that’s needed.
Laurie Wells:
Yeah, thanks for emphasizing that point because it really is such an important aspect to the success of protecting someone and, like anything, it’s probably only as good as the person who conducts the test. And so I’m curious about who can do one of these tests. Is there special training or credentials? How do you ensure that the process of testing gives you reliable outcomes?
Jessica Tredinnick:
It’s an important question. And of course, the answer is not a simple one, so I’ll, I’ll explain a little bit generally yes, anyone can do fit testing in that there is not a certain, specific professional, certification or qualification that’s required in a lot of countries. I’ve seen fit testing, be performed by a lot of different roles within organizations sometimes by the safety manager sometimes by an occupational or industrial hygienist or by occupational nurses. I’ve seen it be done by security teams, supervisors, any number of different roles within an organization might do the fit testing for the organization. But it is required in a lot of countries that the person who’s doing the fit testing has to be competent to do the fit testing. They have to have the appropriate knowledge, skills, and experience to perform the fit test, just like any other responsibility in a workplace.
Jessica Tredinnick:
And in some cases, there are very specific requirements that are outlined by the regulations that apply to fit testing. And so again, it’s important to be familiar with your local regulations that pertain to fit testing. And of course, your local 3M team can help you to do that. So that’s why I say it’s kind of a complicated answer. It’s not black and white. This is a service that many businesses do perform. And so, if there isn’t anybody within your organization that has appropriate knowledge or training, or if there’s no other resource to conduct fit testing internally, you could consider engaging a fit test service provider to work with you and your organization to make sure that you get your fit testing done in a way that is scientifically sound and appropriate. And in compliance with your local regulations.
Mark Reggers:
You mentioned it being a scientific process, and it is quite a prescribed process conducting a fit test when you look at the various protocols around the world, but having that underpinning knowledge of respiratory protection and testing is really critical to that reliability of the fit testing being conducted. I mean, just cause someone has read the user instructions for a piece of machinery doesn’t necessarily make them a competent person in respiratory fit testing as an example. So there are many standards around the world that do list the knowledge and competency that a fit tester should have, which does link back to that reliability of that fit test outcome.
Jessica Tredinnick:
Absolutely. Mark. And that is exactly why many countries have respiratory fit testing, training, and accreditation programs, which aim for a consistent demonstration benchmark to the standards that apply to fit testing in those countries. I think the most well-known of these programs internationally is probably the UK’s Fit2Fit program. And that’s been running for many years, but there have been some recent developments in this area specifically in Australia and New Zealand as I’m sure you know, very well. Of course, you were one of the foundational contributors to the resp fit program in Australia. That’s some really excellent work that has been done there to get that program up and running just within the last couple of years. And then in New Zealand Commit2Fit is another excellent program. And there are others that are being developed across Europe. And in other places, these programs are a really excellent resource in those countries and some of their content is accessible to anyone online. And so it’s a great idea to go and check out the educational materials that are available there.
Laurie Wells:
All right. I want shift gears a little bit, because we’ve spoken about the respiratory fit test and its important role. But I’m curious also about from a manufacturer’s point of view, what does 3M do around its respiratory design and testing when it comes to trying to fit all the workers around the globe?
Jessica Tredinnick:
Thank you for that question, Laurie, this is one of my favorites to answer because there is quite a bit that 3M does when it comes to respirator design and understanding how our products fit different demographics and different facial characteristics. So, three of the things that come to mind are number one, during the new product design process, our respirator designers test several different versions of respirator prototypes to evaluate the fit capability of all of those versions. And that helps to inform the selection of features that balance a good fit with acceptable comfort, and other desired capabilities that are needed by our customers in our respirator products. Another thing that comes to mind is the fact that 3M has fit test labs in seven different countries around the world. So we have the ability to conduct what we call fit panels, which is fit testing on a whole group of people spanning a bunch of different facial sizes and shapes.
Jessica Tredinnick:
We do those fit panels with wearers that represent many countries globally. And then the last thing that I would say about what 3M does when it comes to respirator design with an eye to fit, is that whenever we are considering making a change to an existing product, either because of material availability or product design improvements in order to better meet customer needs, whenever we take on a change, which might impact the fit performance, we conduct controlled testing to evaluate the potential impact of that change on the fit characteristics of the respirator model. Before we actually apply that change and roll it out to our products.
Mark Reggers:
Being a self-confessed respirator nerd. I know I could keep talking about this stuff for a long time, but we probably should wrap it up. So, thank you so much for having a chat with us today, Jess, and sharing your very broad, knowledge and experience. You know, you’ve covered a lot of important information for our listeners, even though we really only have skimmed the surface and dipped our little pinky toe into the world of science and fit for respiratory protection. But hopefully, it gives our listeners a really good appreciation point to think about how does fit work in their world, of things. So thank you so much, Jessica.
Jessica Tredinnick:
Mark and Laurie, thank you both so much for having me. It has been my absolute pleasure and really, truly have me back anytime I can talk about respirator fit for years.
Mark Reggers:
So of course, if any of our wonderful listeners around the world do have any specific questions around the science of fit or respirator fit, testing, the methodologies protocols, setting up fit testing as part of your respiratory protection program, please do not hesitate to reach out to your local 3M contact or office, to assist you in any of these areas as well. So, it’s yeah, we’re here to help that’s for sure.
Laurie Wells:
Thanks for listening everyone. You can listen, subscribe to and share this podcast through Apple Podcasts, Spotify, Google podcast, and most major podcast apps and platforms. If you have questions, topic suggestions, or you’d like some assistance in your workplace, when it comes to the appropriate selection use and maintenance of PPE, you can get in contact with this podcast by contacting your local 3M office or visit our website at mmm.com. This year, we are celebrating the 50-year anniversary of the first NIOSH-approved 3M filtering face piece respirator and the 3M E-A-R classic earplug to all of our customers who have trusted the 3M brand PPE between then and now, thank you. 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. Stay safe out there Mark.
Mark Reggers:
Stay healthy, Laurie. Thanks everyone. Bye.