Category: Analysis

Anything that I have tested empirically, or explain with detailed calculations, or just generally bother to get all the facts straight.

Post #750: Science alert: Proposed cigarette smoke test of “KN95” and other masks

Edit:  This did not work at all.  Not even a little bit.  See Post #790 for details.

In this post, I propose to rate masks on their ability to filter out cigarette smoke.  The particles in cigarette smoke are roughly the same size as virus/aerosol particles.  (Although their chemistry is quite different.)  I am going to use those second-hand smoke particles as my best proxy for human aerosol emissions. The basic idea being that if a particle-filtering mask is good at removing something as small as cigarette smoke particles, it probably does a pretty good job at filtering aerosols in general.

I’m announcing the full scope of the test ahead of time because that’s good science.  This way, I can’t just bury the results if they turn out unfavorable.  (AKA, toss them in the circular file.)  In some sense, it’s as important to know this doesn’t work, as it is to know that it does work, as a way to test masks.

The test is pretty straightforward:  Light a cigarette, hold it under your face, and rate how strongly you can smell cigarette smoke while breathing through the mask.  Less is better.

A cigarette is ideal for several reasons.  One, it provides a consistent burn, meaning, a consistent concentration of smoke particles from one mask to the next.  Two, it’s a readily-available and easily-repeatable standard.  Three, the smoke has been well-characterized.  Four, there is no risk (as with incense) that the material has been doused with molecules meant to volatilize as the base product is burned.  If you smell tobacco smoke, you are smelling smoke particles.  if you smell incense, it’s not clear what you are smelling.

I’m going to start with these five scenarios, hoping to establish some sort of scale:

  1. 3M N95 respirator (new old stock, should be true N95 filtration)
  2. Dust mask with two layers of Filtrete 1900 fabric (~ N85)
  3. Dust Mask with one layer of Filtrete 1900 fabric (~N60)
  4. Plain dust/surgical mask (N low).
  5. No mask (N00)

The first problem is, I still have to manufacture items 2 and 3.  I did a bunch of #3 masks for friends, early in on this pandemic.  I need to make some more, document that, and then go on to make #2 masks.  These should provide known filtration standards below N95.

Then I’ll rate the following six masks on that scale.  These are the masks whose performance I am trying to judge.  Starting with the beat-to-heck 3M dust mask that I have been wearing since the start of the pandemic, that I hope is still working well.  And then some other alternatives that are readily available to the US public.

  1. 3M N95 dust mask (extremely well-used)
  2. “KN95” mask #1, from Twins Ace Hardware in Fairfax
  3. “KN95” Mask  #2, from Twins Ace Hardware in Fairfax
  4. Generic single-use “surgical-style” mask #1.
  5. Generic single-use “surgical-style” mask #2.
  6. Plain-vanilla single layer cloth mask.

The point is to say whether or not you would materially improve your protection from aerosol-sized particles by swapping a plain-vanilla cloth mask for a typical  generic, non-certified “KN95” mask offered as an impulse item at our local Ace Hardware. Continue reading Post #750: Science alert: Proposed cigarette smoke test of “KN95” and other masks

Post #747: Can Kents clarify KN95 chaos? Updated

Source:  Depositphotos.com

Update 2:  This didn’t work, at all.  Not even a little bit.  See Post #790 for details.  You can’t use the odor of cigarette smoke to test mask filtration.

Update:  See postscript at bottom.  The ability of genuine N95 masks to filter smoke particles is well known and well documented.  In that light, my proposed “sniff test” for KN95 masks looks fairly promising.  To the extent that a mask reduces the odor of cigarette smoke, then it is filtering out virus-sized particles.

In Post #740, I noted that my local convenience store had “KN95” masks for sale.    I’ve heard a rumor that one of the local hardware stores is also selling such masks.  (I plan to check that out soon.)  And I exchanged emails with  neighbor who is in the process of purchasing some KN95s, from a couple of different sources, for daily wear at work.

In theory, wearing a KN95 gives you the same protection as an N95 respirator.  So, in theory, upgrading from a cloth mask or similar to a KN95 is a smart thing to do.

In practice, not so fast.  I’ve started looking into the “KN95” mask market, and it is complete chaos.  I guess that’s no surprise.  That’s more-or-less of a piece with the entire Federal response to COVID-19. Continue reading Post #747: Can Kents clarify KN95 chaos? Updated

Post #735: Flu and flu vaccine, part 1. Flu hardly matters.

Source:  US Centers for Disease Control.

The upshot of this posting is that flu doesn’t much matter, in terms of crowding of hospitals during the COVID-19 pandemic. When flu season comes around this year, if we’re still in the COVID-19 pandemic, the flu will add a bit of stress to the hospital system.  But only a bit.

Best guess, based on a variety of sources, the impact of the peak of a bad flu season, on hospital inpatient resources in any one state, will be maybe 5% of the size of the impact of the peak of the COVID-19 outbreak.  So far.  That’s based on number of hospital admissions, concentration of those admissions within states, and average hospital resource use per admission.  A bad flu season certainly won’t help things.  But it’s not really a make-or-break issue in this context.

In terms of things we need to worry about, I’m putting the influence of seasonal flu far, far down my list.  That, no matter what offhand remarks I may hear by public health officials about the dangers of a simultaneous COVID-19 and flu season.

Detail follows.

Continue reading Post #735: Flu and flu vaccine, part 1. Flu hardly matters.

Post #676: I paid my taxes yesterday

Which would not ordinarily be a thing to blog about.  So it’s an odd commentary on the times when doing my taxes was a pleasant change in routine.

I owed a bunch of money to the Commonwealth this year.  I figured that the Governor would appreciate receiving it in a timely fashion, all things considered.  So I did my taxes yesterday.

The deadline for Virginia is June 1 this year.  The Commonwealth says that if you pay by June 1, no penalties or interest are due.  (My tax software said differently, so I’m not sure what the deal is.)

The Federal deadline, by contrast, is July 15.

So this year your Virginia income tax is due before your Federal.  But you have to fill out your Federal forms first, anyway, in order to do the Virginia form.  In terms of the time and hassle cost, tax day here in the Commonwealth is effectively June 1, no matter what the Feds say.

This was my first tax year in pure retiree mode, and boy was it an eye-opener. 

I ran my own little business here in Vienna until August 2018.  And I paid full freight, tax-wise.  As a self-employed person, you start off by paying both halves of Social Security and Medicare.  So that’s about 16% off the top.  (You get a bit of that back, as a deduction.)  And then you pay the rest.  The Town got its slice (Gross Receipts tax), then the Commonwealth, then the Feds.

To a pretty close approximation, my combined marginal tax rate used to be above 50%, and my average tax rate was about 33%.  That’s with stuffing as much as I legally could in an SEP-IRA.

To which my daughter would say, first-world problem.  Because it meant that I had a good job and my business wasn’t going bust.

But now?  No wage income means no social security.  Investment income means many of those lovely tax dodges set up for rich people now apply to me.  Add in some reduction in income, toss with progressive tax rates.  And voila:  I ended paying an average Federal rate of about 9%, and a marginal rate just slightly higher than that.

Which is, oddly enough, how I ended up owing so much to the state.  Back in the day (meaning, when I was working), Virginia taxes weren’t exactly rounding error, but compared to the Federal bite, they looked pretty darned reasonable.

And so, when I figured total taxes for withholding, I did my Federal, and used a rule-of-thumb for State.  Which is now wrong, because I now get all the geezer-related tax breaks from the Feds, but nothing like that from the Commonwealth.

Weirdly, the Commonwealth’s tax bite is the same as it always ways.  But now that my Federal rate is so ludicrously low, I’m kind of resenting the Virginia rate.

In the end, good sense prevails.  I’ve always thought I got excellent value for my Virginia tax dollar.  I’m not going to change my mind on that, now that I’m retired.  As stated, I suspect that the Commonwealth needs my money right about now.  So I got ’em done.

 

Post #618: Blue skies, a followup

White Clouds in Blue Sky ca. 1996

My wife found the definitive article in the Washington Post.  I’m not crazy, the air is significantly cleaner now, thanks to lockdown.

That article also has links to research suggesting that long-term exposure to “PM2.5”-type air pollution (fine particulates) explains much of the variation in coronavirus death rates across the country.

As I noted in an earlier post, Italian research points vaguely in that same direction.  Wuhan had notoriously bad air pollution, as did the hardest-hit region of Italy (the Po Valley).  And air quality in New York is not so good.  And, to be honest, that doesn’t bode well for DC.

So the sky really is better-looking these days.  And if the Italian analysis is right, the reduction in particulates helps slow the spread of disease.  But our long-term exposure to particulates likely increases the mortality rate among those who fall ill.

 

Post #614: The sky is blue

 

White Clouds in Blue Sky ca. 1996

Source:  Clipart-library.com

No, really.  Stick with me here.  What I mean is, have you noticed that the sky is unnaturally blue.

This is Virginia, for crying out loud.  The spring/summer sky should be, at best, pale blue, edging toward fish-belly white.  But day after day, it’s like we’re living at high altitude in the Rockies.  Perfect beautiful blue sky.

Did you know that if we shut down all industrial activity and fossil-fuel use, the impact would be to raise the earth’s temperature significantly?  In the short run.  And only in the short run.  True fact.  That’s because we release both C02 and particulates/aerosols.  C02 warms the earth, but aerosols cool it.  The C02 is very stable, remains in the air for a enormously long time.  Most particulates and aerosols would rain out/fall out in a matter of weeks to months.

Basically, the longer the shutdown, the better the sky should look.

But apparently this is perception of better air in the DC area is purely in my head.  Because empirically, somehow, the air quality index for DC is … no different than it normally is.  Per this web page.

So I’m a little perplexed.  You’d think, from the traffic reduction alone, you’d see better air quality.  But … no.  I think I’ll keep looking around to see if anyone can explain this.  Or maybe the Air Quality Index doesn’t quite measure what I think it measures.

Post #612: Election confusion on two fronts

First, it looks like the Governor is trying to get all May elections postponed until November.  I think that’s the correct thing to do, all things considered.

Second, there still seems to be considerable confusion in Town over campaign finance laws.   Twice in the past two days I’ve seen or hear of things that lead me to believe that many people in Town still either don’t understand what the law is, or are deliberately misrepresenting what the law is.

I heard that, sometime in the past couple of days, somebody claimed that a sign was illegal because it had some candidates names, but no “Paid by …”  line noting the source of funding.  That’s wrong.  And we all know that’s wrong, because we’ve never had “paid by” lines on the yard signs before.  And I also see that, this year, one candidate actually does have a “paid by” line on her signs.  That’s also wrong, if she’s trying to convince people she’s complying with the CFDA.  But as long as we all recognize that’s just a bit of let’s-pretend, I think that’s harmless.

If you actually want to comply with the CFDA, you have to have duly-constituted and registered Virginia Political Action Committee.  I know because I did that last year, to make sure I understood the process.  And detailed what the CFDA does and does not do, on this website.

Looks like it’s time for a refresher course on the Virginia CFDA.

In a nutshell, no campaign finance disclosure laws apply to Town of Vienna elections.  That’s the way it has always been, ever since Virginia pass the Campaign Finance Disclosure Act.  (CFDA).  The only change this year is that they’ve added a clause that says, if you spend $25,000 or more, as a candidate, in a Town election, then yeah, in that case, you have to obey the CFDA.

So, briefly, with citations as to source:

Campaign finance law for Virginia Towns with under 25,000 population.

There are none.  So let’s start with the basics.  No campaign finance laws apply to Town of Vienna elections.  I wish they did (Post #272, from May of last year.)  Not unless the Town Council slipped in a piece of last-minute legislation. Or a candidate is planning to spend more than $25 grand, which I think is way beyond unlikely.

So if somebody tells you that (e.g.) some sign is illegal because it doesn’t comply with Virginia law, they just haven’t read the law.  Or they are trying to pull a fast one on you.  If somebody puts a “paid for” line on their signs, they’re either trying to convince you of something that’s not so, or they’re planning to shell out more than $25,000 in their election bid.

But that last one is easy enough to check.   If somebody’s complying the the CFDA, and that “paid by” line has any legal meaning, they have to have a Virginia PAC.  No PAC?  Then a “paid for” line is just an additional bit of election-year nonsense.  It’s easy enough to search all the active Virginia-registered PACs, right at this link.  Have a look for yourself, if you care.

It’s a simple test.   Got a PAC?  No?  Then any “paid for” line you see is the politician’s variant on “guaranteed not to turn pink in the can“.

So let’s all go read the law, because boy am I tired of having to explain this.  And, interestingly, it changed since the last time I looked at it:

This is § 24.2-945. Elections to which chapter applicable; chapter exclusive.

The provisions of this chapter shall apply to all elections held in Virginia, ... except nominations and elections for ... (iii) town office in a town with a population of less than 25,000, ....

Emphasis mine. But they’ve added a new exception since last year.  If you spend in excess of $25,000 on the election, you’ve got to abide by the CFDA:

The provisions of this chapter shall be applicable to a candidate for a town office in a town with a population of less than 25,000 if (a) such candidate accepts contributions or makes expenditures in excess of $25,000 within the candidate's election cycle

And then it goes on to say, or if the Town votes to put itself under the CFDA.  Herndon actually did that about 7 years ago.  But not, to my knowledge, the Town of Vienna.  Last time my wife brought this up at a Town Council meeting (Post #507).  That was met with roughly the same reaction as a fart in an elevator:  Dead silence and dirty looks.

Why do I know the law?  Because I bothered to go through all the steps to form a legally-registered Virginia PAC (Post #272).  I needed to know, first hand, exactly how burdensome it was, before I suggested that the Town vote to put itself under the CFDA.  I even wrote up a guide to doing all the steps required to form a legally-registered Virginia PAC.  I offered to make that guide freely available to anyone who wanted it if the Town ever voted to put itself under the CFDA,.  My wife got up in (one, several, I forget) Town Council meetings and pleaded with the Town to put itself, for reals, under the CFDA.

Which is also why I find people who don’t know the law, but throw it around to intimidate people, or mimic it to impress the gullible, I find that irksome.

Actually complying with the CDFA requires some significant effort.  There are a lot of legally-required reports that must be filed, for example.  I went through that, myself, forming a PAC, because I did not want to recommend that the Town put itself under the CFDA if that process was impossible to comply with.

But the short and simple answer is, the CFDA simply does not apply to Town of Vienna elections.   This year.  Just the same as it didn’t apply in any prior Town election.

Unless you plan to spend $25,000 or more.  That’s the only change for this year.

Post #606: US Census: If you’ve gotten “the postcard”, you’re being unhelpful

Look familiar?  If so, you’re being a bad person.

We have all gotten our notices in the mail by now requesting that we get on-line and fill in the US Census.  I’ve neglected mine.  Which is kind of horrifying, considering that I’ve actually done a bit of survey work professionally. And used the Census data professionally.

When I finally got “the postcard”, I knew I was being a bad actor.  Assuming that Census does this in a standard manner, getting “the postcard” is a mark of shame.  So it was time to fill in the Census.  Which I have now done.

I timed it.  It took me 10 minutes, for the four people in my household.  Which is typical.  But I messed something up, so I thought I might mention that.

The plain language of the Census form says to count all individuals who were staying in your house on April 1.  But that’s not correct.  If you have a child who was supposed to be away at college on April 1, you are NOT supposed to report them as living in your household in April 1.  Even though they were.  They will be counted as they usually are, in their respective college towns.

Here’s a link go the US Census page on that.

Unsurprisingly, the last question specifically addresses that.  Census gives you the opportunity to flag that college student, so that Census can (somehow) identify them based on some college reporting them.  Presumably, because Census will find a person with my daughter’s exact name and date of birth, at some college near to my home, they’ll take her off of the count for my household, and retain it on the count for the college.

Now let me explain the postcard of shame.  I’m assuming Census uses standard survey protocols.  Typically, in a mail survey, you’ll get a first notice in the form of a full letter.  If you don’t fill it in, there will be a followup in the form of a short letter, saying, in effect, please read the prior letter.

But only the truly uncooperative get the postcard.  The postcard is typically used for the second followup.  The practical reason for using a postcard for second followup is that, by that time, you’re not worth the price of a first-class stamp.  If you’ve been enough of a jerk as to ignore the first and second notices to do what you are legally obligated to do, chances are you aren’t going to cooperate no matter what.

In other words, by the time you get to second followup, the likely yield is so low that you’re practically just not worth bothering with.  But it’s still cheaper than having to send out the paper-copy Census form.

And vastly cheaper than having in-person followup, which I’m not even sure they are going to be able to do this time.  Census taker was always a somewhat hazardous occupation.  Now, it’s not even clear they are or should send people door-to-door, to deal with the least-cooperative people among us.

The upshot is that the US Census is among the many things that COVID-19 has scrambled.  It’s a pretty good guess that a lot of people are not going to be counted.  Do your part to fix that.  Get on line and fill out your Census form today.

Getting our fair share of Federal, state, and local government money — not to mention our seats in the U.S. House of Representatives — all depend on that Census count.  The information they ask for is minimal.  Name, date of birth, sex and race/national origin for every person in the household.  And do you own or rent the place where you live.  That’s it.  Get it done.

 

Post #594: Expedient masks, part 2: What can you buy

Source:  Amazon.com

As our Federal government stumbles toward a public mask policy at a glacial pace and with off-the-cuff advice, let’s see if we, the people, can get ahead of the game on this one.

The just-prior post already established that a reasonable home-made mask will do just fine for protecting others.  This next series of posts is about protecting yourself.  

And this post is about what you can buy, right now.  Its about expedient masks, meaning anything you can buy or make to serve as a face mask, that would (we hope) never be used by health care workers.  Anything other than real medical masks — either N95 (or equivalent hardware-store P95) or proper, certified surgical masks — such as might be used in a hospital.

Upshot:

If you want to buy a plausibly-effective sanitary mask, right now, for wearing in public, it looks like your sole option is disposable “surgical” masks bought through Ebay.  As discussed below, these are not actually proper certified surgical masks, and some of them are in fact simple “single-use” masks, as described in my just-prior post.  You can order the same thing through Amazon, but typical wait times are about a month.  I list out the features you want to see in those masks, if you buy them, below.

Caveat emptor:  I just looked at Ebay, and there are clearly a lot of unscrupulous sellers, and a general air of on-line panic shopping.  If you absolutely have a need for these, consider it.  But be aware that you may well be wasting your money.

In addition, anybody who is in the business of throwing away N95 or P95 masks (respirators) should read this analysis of how long an N95 may be re-used.  The answer is, putting aside the issue of sterilization, a long, long time.  Which is good, because (e.g.) the screeners at Dulles Airport have been asked to re-use their masks on a permanent basis.  So, even if you don’t re-use them now, it’s probably time to start separating them from the rest of the waste stream and retaining them.

What’s off-limits, what’s available on Amazon

This post is about masks that you can buy, right now.  And, separately, how you might modify them to improve their filtration capabilities.  I’m not going to spend a lot of time on this, because I suspect that when CDC issues guidance that Americans should wear masks when in public, anything for sale will disappear from the shelves.

I am sticking with Amazon, for the time being, because they appear to be doing things responsibly, as discussed below.  As I read it, right now, if you see it for sale to the general public on Amazon, that’s because it’s not needed by the US health care system.  That is not uniformly true of places like Ebay.  So I’m only going to look at items that are for sale on Amazon.  I may check availability of those same items on Ebay.  Clear enough?

I spent some time explaining the technical jargon in the last post, so I am going to feel free to use those terms around here without explanation.  Just refer the last post.

But this is not about protecting yourself, at the expense of the health-care workers.  In my last post, I explained why hospital workers need N95 masks and you don’t, under the section on aerosol transmission of disease.  So let me list not just the things you can buy, but the things you shouldn’t buy.

N95, P95, P99, P100:  NO. 

Source:  Wikipedia

If you stumble across anything rated N95 or P95 or better, just leave it alone, unless you plan to purchase it for donation to your local hospital or fire and rescue unit.  You should not be able to find these for sale now, but that’s only because responsible companies have withdrawn them.  (See Home Depot in just-prior post.  I don’t think the Federal government has taken any action to make the sale of these (to other than medical/fire/rescue providers) illegal. This class includes not only classic N95 “masks” as above, but (e.g.) anything like the P100 paint respirator pictured at the very top of this posting.

Again, you don’t need it.  Health care workers and fire and rescue units are going to need them.  See my prior post on why health care workers need them, and you don’t.

Surgical masks certified for medical use:  NO.

Source:  Wikipedia.

I’m not sure if you can find proper certified surgical masks for sale or not, but ditto the remarks above on N95s.  Leave them for health care workers.  Please see the prior post for a discussion of the difference between single-use masks and surgical masks, and the filtration standards.

Note that several large-scale controlled clinical trials show that surgical masks are just as good as N95 respirators at preventing flu infection among hospital workers.  An excellent summary is here, at Smart Air.  So, in a pinch, you bet hospital workers would use those if N95 respirators are not available.

Read my just-prior post for the difference between certified surgical masks, and “single-use” masks, which you can buy, and which are not critical to the US health care system right now.

Things that look like surgical masks but are not certified for medical use, available on Amazon, and are probably “single-use masks”, not surgical masks (defined below):  I would say, yeah, for now, probably YES. 

Wait times are long (typically one month) on Amazon, but this same sort of produce appears widely available (for now) on Ebay with short delivery times promised.

Source:  Amazon

What makes me say that?  Amazon is one of the responsible vendors who have pulled all masks that can be used by medical personnel and first responders.  Anything like that, their pages now have this wording:

Available only for hospitals and government agencies directly responding to COVID-19

For example, Amazon has withdrawn not only N95 respirators, but high-quality nuisance dust masks as well.  They have withdrawn surgical masks that appear to be certified for medical use.  (Note that those masks list their actual filtration rates, whereas the ones that remain for sale do not.)  To me, that suggests that they really have gone through their inventory and pulled out anything that would be useful to medical providers or first responders.

I have to infer, then, that if Amazon doesn’t say that, then there has been some professional judgment that the item in question is not needed by health care workers.  I am not 100% sure about that, but at some point, I have to believe that Amazon knows its business, and has done the right thing, and has stopped sale of all items that would be useful to health care workers (as Home Depot has done.)

An incredibly helpful and succinct discussion of single-use masks, surgical masks, and N95 respirators, along with considerable other helpful information (e.g., can you wash disposable masks) can be found at Smart Air.  If you want to get up to speed on what’s what, for actual medical supplies, that’s the place to start.

So, provisionally, I’m going to say, despite some misgivings, these are probably OK to buy.  I’m guessing that most of them are, in fact, “single-use masks” and not surgical masks.  If (note, if) those were manufactured to any standard, it would be a Chinese standard, and they would be able to filter out 95% of large aerosol droplets (3 microns), but would not filter something the size of a virus.  Proper surgical masks, by contrast, will filter out virus-sized particles.  Again, see Smart Air for a discussion of mask standards.

Even though these are not certified, and some appear to be poorly made, many of them do appear to have the right construction:

  • Three-ply construction, with
  • A layer of melt-blown fabric, and
  • A metal strip at the bridge of the nose.

To the extent that these are fairly good at filtering the air, that’s due to the melt-blown fabric and the nose piece.  See prior post for “melt-blown fabric”.  (You don’t know the quality/specs on the melt-blown fabric, but at least it has some, suggesting that it has filtering ability above-and-beyond what you’d get from just paper.) The nose piece is required to seal up what would otherwise be the largest air leak for the mask, right at the bridge of the nose.

Finally, multiple large-scale controlled clinical trials have shown that proper, certified surgical masks (not single-use masks) work just as well as N95 respirators at keeping hospital workers from catching the flu.  (Cite Smart Air). Whether or not whatever-these-are on Amazon — single-use masks or possibly uncertified surgical masks — would work as well as certified surgical masks is a complete unknown.  For sure, single-layer single-use masks, even if they were built to the Chinese standard, have no ability to filter virus-sized particles.  They would not have the filtration capacity of a certified surgical mask.

Check the delivery time before you buy.   The main catch here is delivery time.  That nice-looking white mask above?  I searched “face mask”, sorted by descending customer rating, and checked the earliest promised delivery time for the first 20 entries.  Median earliest promised delivery date was 26 days.  Three entries promised delivery within six days.  Two of those were of such low quality (by description and customer comments) that I doubt they would work.  The third was priced at about three times the going rate for masks.

The upshot on delivery is that a) for the typical product, it’s going to take a month, and b) anything promised for near-term delivery is either too poor to be useful, or (in one case) priced at several multiples of the going rate.

I re-sorted by descending price, and spot checked.  Even for very large orders (e.g., 1000 masks) first promised delivery dates were about a month away.

To summarize:  It appears that Amazon has stopped selling anything that has been judged useful to the medical or first-response sectors.  The only safe thing is to assume that whatever you are seeing on Amazon, at best, meets the Chinese standard for filtration for single-use masks.  If so, those would provide significant filtration against droplets, but limited filtration against aerosols and virus particles.  (I.e., they aren’t as good as real surgical masks).  Some of the disposable masks appear to have proper construction, per bullet points above.  If so, you could reasonably assume that wearing them would offer you some protection, but that is just an assumption.  The best of these have melt-blown fabric (the “filter” portion of a certified surgical mask), but you have no way of knowing what type of melt-blown fabric it is (i.e., how well it would filter air).  Even with that, you should expect about a one-month wait time for anything that looks worth buying, or feed the occasional price gouger who is promising an earlier delivery time.

Can you get them now, on Ebay?  Yes, that appears to be true.  If you go that route, look for three-ply construction, metal nosepiece, melt-blown fabric, and some claim as to bacterial filtration.  You have no idea whether the claim is right or not, but so be it.  A fair price appears to be in the range of $0.70/mask or so, in large lots.

Fabric sports masks:  YES, if you are wiling to modify it.  What you can routinely get does not appear very effective as a protective mask, because these are designed to “breathe”.  If you can sew, you can add a lining.  If not, you can try to add a paper lining.  You will definitely want to add a wire nosepiece to provide a tight fit across the bridge of the nose.

Source:  Amazon

At present, everybody says that any type of fabric mask is OK. Masks like that are frequently sold as pollen/pollution masks for outdoor exercise.  Amazon has a wide range of them. Most (perhaps all) are really not adequate for this task, consisting of a single layer of cloth.  Because these are exercise masks, they are made to “breathe”, which is what you don’t want, right now.

At the minimum, you’d have to line these with something.  Practically speaking, I think you’d have to resort to lining these with paper towels.  That provides some protection, but not much (see prior post, last section).  You would also want to take a bit of wire and either duct-tape it to the mask, or thread it through the mask, to provide a metal nosepiece for sealing the mask to your face at the bridge of your nose.

And, as with the disposable masks above, most have one-to-two-month shipping times.  I saw a handful with promised delivery times of a couple of weeks.  Weirdly, I did not find these on Ebay.  Maybe I just didn’t have the right search terms.

I’m not going to pursue these any further.

“PM2.5 masks”:  Eh, I’m not even sure what this means.

Source:  Amazon

There is a huge range of masks — some hard-surfaced, as the one above, some fabric, some hybrid — that are sold as anti-air-pollution masks.  That is, they claim to filter out particulate matter of 2.5 microns in size (PM 2.5).

Near as I can tell, as discussed in my prior post, there are no standards and there is no testing of these masks.  Some probably work.  Some probably don’t.  I have no way to tell.  I’m not going to discuss these further.  The few that I checked appeared to have delivery days 6 weeks away or so.

Caveat emptor.

Various loose-fitting masks and bandanas.  These protect others, a bit, but the lack of any seal means they provide very limited protection to you.

Source:  Amazon

And, of course, even these have promised delivery dates 6 weeks out.  These are single-layer loose-fitting cloth mouth coverings.  Better than nothing, but probably not as good as just pulling your t-shirt up so it covers you nose and mouth.  I don’t see value here.

Etsy hand-sewn cloth masks.

I did not pursue this option, but I would assume that some are available.

My next posts will discuss making masks.