Thread by @AdvancedTweaker

It’s pool and beach season! Will a respirator work for swimming and water parks (or shower sans hair washing)?

Using my PortaCount 8020A, I tested the most accessible & affordable water-resistant respirator, 3M Aura 1870+, after 6 and 8 hours of wear at the pool (1.5hrs total of swimming) across a month. I did install a SIP valve in it – you get thirsty!

To see if you really need a water-resistant version, I then tested the 1870+ against a non-water resistant 3M Aura respirator with similar rubbery straps, the 9205+.

The results were surprisingly good all around.

(photo is a fresh and used 1870+ side by side)

Here are my 1870+ scores for swimming. Thank you @fittesttheplanet for the little probe plug that made re-testing a probed one possible!

I also wore swim goggles during all “soaks”.

Baseline - Fresh 3M 1870+, no SIP valve, OSHA protocol

Normal breath: 144
Deep breath: 103
Head side to side: 167
Head up and down: 120
Speaking: 49
Grimace: 179
Reaching: 88
Normal breath: 145

Score w/ grimace: 106.34 (99.06% of air filtered)
Score w/o grimace: 100.51 (99.01% filtered)

Note: I have tested the SIP valve in the past and it did not have any impact on fit testing scores. The focus here is on trends across time. It is possible that I installed it differently this time, but I don’t think this is likely with the follow-up scores. I did not have a way to seal the probe when I started using the respirator.

Time 1 – 3M 1870+ After 6 hours (1hr swim, always head above water, no extra splashing), with SIP valve installed. Respirator was almost dry when tested.

Normal breath: 157
Deep breath: 83
Head side to side: 145
Head up and down: 108
Speaking: 58
Grimace: 87
Reaching: 80
Normal breath: 129

Score w/ grimace: 95.74 (98.96% filtered)
Score w/o grimace: 97.13 (98.97% filtered)

Time 2 - After 8 hours (+one pool session, 2 hours, with about half hour more swim, purposefully splashed as much as possible toward the face). Respirator was still wet when tested.

Normal breath: 78
Deep breath: 58
Head side to side: 126
Head up and down: 91
Speaking: 75
Grimace: 92
Reaching: 83
Normal breath: 122

Score w/ grimace: 85.62 (98.83% filtered)
Score w/o grimace: 84.78 (98.82% filtered)

Comparing the three times, score with grimace went down by barely 0.25% of leakage loss.

Same thing without grimace, which is how OSHA scores are usually reported (but I like to look at both).

To me, this loss is not a big deal, especially outdoors!

Okay, that’s great! But do you actually need a water-resistant respirator for splashes?

I probed a fresh 1870+ and a 9205+ for PortaCount testing and sealed the probe. Same body and rubbery strap material.

Wearing each respirator, I stuck my face directly under a running cold shower for two minutes. I tested the 9205+ first, as I expected it to soak through. I ran the stopwatch to see how long it might take to start having trouble breathing in the 9205+. It took two minutes, hence the time choice.

I tested each one right after the soak.

1870+ after 2min soak

Normal breath: 111
Deep breath: 67
Head side to side: 86
Head up and down: 85
Speaking: 81
Grimace: 97
Reaching: 77
Normal breath: 81

Score w/ grimace: 83.93 (98.81% filtered)
Score w/o grimace: 82.35 (98.79% filtered)

9205+ after 2min soak

Normal breath: 66
Deep breath: 62
Head side to side: 92
Head up and down: 53
Speaking: 38
Grimace: 110
Reaching: 63
Normal breath: 102

Score w/ grimace: 65.52 (98.47% filtered)
Score w/o grimace: 61.94 (98.39% filtered)

Here are my fresh 9205+ scores for comparison. It does score lower on me than the 1870+; the nose wire seems to be a bit stronger on the latter one.

Normal breath: 106
Deep breath: 50
Head side to side: 103
Head up and down: 75
Speaking: 48
Grimace: 71
Reaching: 68
Normal breath: 130
(Overall fit factor, with grimace = 73)

So only 8 points drop when soaked, ~0.2% filtration loss here; could easily be just from random testing error.

Conclusion: There can be slight loss of respirator effectiveness with fluid exposure, even with fluid-resistant respirators, but it seems to cap out. We do not know whether it's fit or filtration just from testing with a PortaCount.

Even non-fluid resistant respirators will maintain really good performance in wet conditions. So getting rain on your respirator is not a problem – as long as you can breathe! I only had trouble breathing in the soaked non-fluid resistant one. The one I swam in gave me no problems, even with my face in the shower stream!

Breathing harder with a soaked respirator can possibly lead to quicker fit loss, but I did not test this. The 1870+ was definitely dry on the inside, but the 9205+ was damp. Both dried out noticeably in ~10 minutes, even when completely soaked!

I still do think it makes sense to wear a fluid-resistant respirator whenever you expect to get water on your face 😊

Whoops can't edit this, it's @FitTestMyPlanet my bad 😔