Thread by @Mlloyd_2010

I’ve been seeing a push to get MCPS teachers KN95 masks.
Obviously, getting vaccinated is hugely important.
Ventilation in schools is important.
…and masks are certainly part of the mix keeping the air clear, because after all, #COVIDisairborne

As you are thinking about mitigating occupational hazards, you’ve got to think about the NIOSH hierarchy of controls. That upside-down pyramid is a good reminder to take care of the most important things first. cdc.gov/niosh/topics/h…

That would be elimination – which we’d all prefer to see #Covid eliminated from @MCPS our schools…and preferably our lives!

Physically removing the hazard from the workspace gets priority here because the other methods of control introduce the potential for error and processes that can go awry, even with best intentions.

That “elimination” step on the hierarchy of controls is why #ventilation in schools needs to have top priority to protect MCPS staff and our kids.

That’s also why it’s really troublesome that MCPS has not really answered community questions on ventilation in schools –
Questions that folks have asked (repeatedly) and are still unanswered:

What we don't know is how MCPS’s “diamond rating” for each school was determined. Specifically, @MCPS needs to be transparent about:

What are the HVAC filter levels installed at each MCPS school. When were these filters last replaced?

What are the filtration recirculation airflow rates for each classroom? When were these flows last tested?

What is the air exchange rate in each classroom? When was the exchange last tested?

What is the maximum CO2 in each room after the room has been occupied all day? #IAQ experts are using CO2 to help hone in on problematic air exchange

Many have said it, but @PCMC1 said it very succinctly:
MCPS says it is following the COVID playbook, but they haven’t been transparent about giving #MoCo confidence that they are doing it A) correctly & B) equitably.

In short, clearing the air (ventilation) and good masks will make the difference.
Let’s look further down the hierarchy of controls - all the way to personal protective equipment.

Now MCPS has shared that they are giving MCPS teachers “high quality KN95 masks”
I’m concerned that MCPS offered KN95s and folks are just accepting that.

Has anyone like @CaitlynnPeetz14 @KateRyanWTOP or @KevinLewis7News pressed MCPS on why they are offering masks for the Chinese manufacturing standard, when NIOSH-approved N95s are fully available in the US?

In order to be protected, you’ll need to be sure you have a tight seal around face - so take a good look in the mirror and make sure there are no gaps around the bridge of your nose, or under your chin, or around your cheeks.

And while it’s not impossible for workers to get a good tight seal for their mask with a KN95, it’s a lot less likely than using an N95.

Let’s look at those design differences between the KN95 and an N95:

The standard itself:
The GB2626-2006 is the Chinese standard itself, not something specifically associated with the product

https://twitter.com/EricHerboso/status/1479596753028591622?s=20

As the Chinese standard, GB2626-2006 KN95s do have some design specs associated with them. That said, there *isn’t* a Chinese regulatory agency that ensures that a respirator manufacturer actually meets the KN95 standard.

There was already a problem with counterfeit NIOSH-approved respirators in the US before the pandemic. cdc.gov/niosh/npptl/us…

How do you think the situation is for counterfeit KN95s given that there is no regulatory agency checking on that? You end up with this:

https://twitter.com/MollerMichele/status/1479579636728315907?s=20

The N95 standard is for the respirator blown fiber itself – It can filter out 95% of airborne particulate. The fibers are actually electrostatically charged, giving a protection boost by helping “catch” particularly small particulate in the air.

There are also some differences in the performance standard itself between KN95s and N95s – but the real story is how deficient some KN95s are compared to what their true performance should be:
cbc.ca/news/canada/sa…

….but even if the standards are on par, it’s the fit that is really important!

Sizing:
Given that the KN95s are a Chinese standard, they are sized smaller than N95s.
Depending on gender differences/facial structure, that might not be a deal-breaking difference.

Ear loops:
Virtually all KN95s use an earloop design, While the ear loops are great for easy on/easy off, they often don’t seal as well around the face.
That can be corrected using an additional strap to hold the ear loops firm behind your head.

But using those additional straps are probably not as good a choice simply using a NIOSH-approved N95 in the first place.

On a personal level, if you are using a KN95 to run to the grocery store, I’m not going to fault you.
But MCPS has a pretty substantive operating budget, and in order to protect teachers and staff who are working in schools ALL DAY LONG, they deserve better.

The US CDC NIOSH approves (not certifies!) filtering facepiece respirators like N95s.
The standard has been in use for a long time and if COVID was a chemical hazard, MCPS would be bound to run a respirator program per OSHA’s 1910.134.

OSHA’s COVID rules are at the supreme court now (eek), but regardless, we have been hearing from infectious disease experts for awhile about how your cloth mask isn’t going to cut it against omicron.

I’ve seen a lot of speculation about whether the KN95s given to MCPS teachers were given FDA approved KN95s…but that is a bit of a rabbithole.

The FDA respirator approval whether the respirator is dealing with blood splatter and other aerosolized liquid droplets. That doesn’t matter for MCPS teachers aren’t healthcare workers and don’t have to worry about aerosolized blood splatter.

They do need to worry about good fit though – and the earloop design for KN95s just doesn’t establish the same quality of seal that an elastomeric N95 can.

If we’re making calling for good quality for MCPS teachers – let’s make the call for N95s. That is especially true for teachers spending long hours in crowded classrooms.

It’s time for teachers (and kids alike) to ditch the cloth masks – Take a look at this graphic from the WSJ about how time affects your ability to be infected based on different mask/respirator types:

https://twitter.com/TerriGivens/status/1477830833260036098?s=20

Even the difference between a good fitting surgical mask and a N95 make a difference – w/ studies showing a significant cumulative reduction in ambient air concentration of the virus with “better” masks.

https://twitter.com/COVID19arXiv/status/1479247454822445066?s=20

Overall that is going to help with potential infection or transmission!

In 2020, there was a huge shortage of N95s for healthcare workers and first responders.
The shortage was so severe that OSHA allowed some employer flexibility for employers that managed health care workers & then extended it to other employers managing respirator programs.

One bright spot on the supply chain is that the US ramped up domestic capacity (and import) of NIOSH-approved N95s and *there is no longer a shortage of NIOSH-approved N95s in the US*.

When we were really in the thick of it (mid-2020) FDA did have an emergency use authorization for non-NIOSH-approved respirators, but with N95s back and fully available, FDA has withdrawn that EUA for KN95s (etc) fda.gov/medical-device…

The main point there is that FDA (and OSHA and EPA) all recognized the restoration of availability of N95s and stopped recognizing respirators from other jurisdictions.

It’s a good time to point out that you N95s are readily available from reputable suppliers like ProjectN95
shop.projectn95.org/respirators/

The bottom line is that sick MCPS teachers aren’t going to be able to teach – in person OR remote.

It is problematic to see MCPS offer KN95s, when #publichealth officials recommend N95s - and they are fully available in the US.

After we’ve advocated for vaccination, community testing, and ventilation, *then* it’s time to have the discussion about good quality masks that fit well and can protect MCPS staff and teachers – NIOSH-approved N95s, not KN95s.