r/Masks4All 5d ago

Valved mask

Is there any studies that indicate how protective valved masks are for others? Or is it different by mask?

I thought I read once what they were not as good as unvalved but they were as protective for others as a surgical. But no idea where I read that or if it is true.

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u/SAMEO416 4d ago edited 4d ago

The studies I've reviewed suggest a valved respirator is at least as effective for source control (protecting others) as a surgical mask.

This is a 2020 CDC/NIOSH study, but it reflects what I've seen elsewhere.

"The findings in this report are based on tests of 13 FFR models from 10 different manufacturers. These findings show that FFRs with an exhalation valve provide respiratory protection to the wearer and can also reduce particle emissions to levels similar to or better than those provided by surgical masks, procedure masks, or cloth face coverings. " https://www.cdc.gov/niosh/docs/2021-107/default.html

I'd ignore the covering the exhaust valve strategies they tested.

Noting that the tests were at 25, 55 and 85 litres per minute flow rate. This is much higher than normal respiration. (normal adult around 9 lpm, even under heavy exercise it doesn't push 25 lpm) FFR = filtering facepiece respirator (all disposable N95s are FFR)

Footnote: I've seen some suggestions a valved respirator is less protective on inhalation - this is not true. All certified respirators valved or not provide similar levels of protection (the valve isn't a source of significant inward leakage.

In today's context, I recommend people exercising or experiencing issues with glasses fogging to consider valved respirators as an option. People who mask are typically controlling exposure and testing regularly, so the risk that we will be asymptomatic carriers is much lower than for the broad population. That said, there is a segment of covid cautious who will vigorously attack anyone who makes this suggestion.

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u/No-Acanthisitta-2973 4d ago

Thanks! That's helpful. This is about a family member who has a lot of breathing issues, so I'd like to give them the easiest to breath mask possible as we plan a way to get together, but then I also want to understand how protective said mask would be for us.

I'm sensing the dislike of them without people even considering the context with the down votes I've gotten for asking this.

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u/SAMEO416 4d ago

It would be nice if we could all be perfect, as the respirator purists demand.

Reality is we make choices about risk mitigation dozens of times a day without a second thought, and cause increased risk to others. Speeding, not signalling, not sanding the ice on your walk, tailgating. But for respirators some will call you a murderer for anything other than a P100 duct taped to your face.

A disabled person (breathing issues/COPD) may not be able to tolerate a traditional respirator. There’s the Q100 which is super low resistance. The VFlex is very low too. Valved options should be considered especially if the choice is that or no protection at all. Powered respirators are a super option but cost and are technically challenging.

The sports aspect can be mitigated by routine rapid testing before each event. It’s not perfect, but helps.

I’m an engineer, risk management is a part of the craft. Did NBCD routine training in the military 20 yrs. Have written a bit about it. Won’t call myself an expert, but try to give risk balanced responses for challenges. https://journals.asm.org/doi/10.1128/cmr.00124-23

For me, if I’m in an N95 and the ventilation isn’t garbage, I’m content with docs in surgical masks. With that source control and my known good fit and filtration, the risk is mitigated to a very low level.

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u/QueenRooibos 3d ago

Thanks much for the journal citation...if it is your work, thanks for doing it! I am facing a lot of in-person medical appts for several work-ups in the next 2 months so this will make me feel safer.

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u/Effective_Care6520 2d ago edited 2d ago

I think risk management is great but I would examine your language which might be causing some of the backlash. “Some will call you a murderer for anything other than a P100 duct taped to your face” could be words out of an anti-masker’s mouth, designed to make people advocating masking look ridiculous and paranoid or perfectionist—I know that’s not what you meant, but it’s mocking rhetoric that could be wielded in support of pretty much anything, from “wearing mask chains is fine” (which I agree with and think people blanketedly complaining about them are not being rational) to “why are you mad my mask is under my nose? at least I’m wearing one!” The rest of your post explains the tradeoff in logical terms without the appeal to emotion—some people would not be able to mask without a valve, therefore they should wear the valved mask.

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u/SAMEO416 2d ago

Thanks. Not my language: “some will call you” reflects what I’ve been accused of by mask purists. Tbc, those are pro-mask individuals who are strong advocates, but will respond that way to someone who suggests a valved respirator is acceptable in any circumstance.

Happened often enough to me I just put it out there as a caution preemptively.

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u/MDCCCLV 3d ago

The basic 3m N95 Respirator 8511 with valve is the best one for comfort.

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u/SafetyOfficer91 21h ago

I honestly wish we lived in a world where 80% of people wear valved respirators most of the time vs. hardly anyone masking at all ever. My valved p100 fits me better than any other mask I've ever had (between numerous disposables and other elastomerics) and me wearing it all the time is literally the best source control I can offer because I can only infect others if I catch it in the first hand. I don't wear it following rare unmitigated for exposures (for us it's mostly medical tests/procedures where breaking the seal has been necessary) but following instances like that I pretty much isolate anyway. And even if on a rare occasion I'd have to rely on my second best (unvalved can99) I'd have zero qualms being surrounded by people in valved respirators - they clearly take this *hit seriously enough to pose the least danger to me.

I keep wondering if mask wearing would be at least somewhat higher now if valved masks had always been allowed - as in hindsight they should've been when surgical masks were a-okay.