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Using expired N95 masks?

Posted: 2020-03-19 06:45pm
by Shroom Man 777
As a last resort. I have a bunch and the vexing thing is that a bunch have had their nosepiece foams degrade, so there are particles lining the interior of the mask.

Yes, I know ideally these would've been discarded the second they became expired (there are US gov't guidelines on using expired but wholly intact N95s while noting their reduced effectiveness, so these shouldn't be used in OR or hospital settings). More so now with bits of foam dotting the insides posing inhalation risks.

But in austere conditions, could one somehow clear out the foam specks and use these to limited effectiveness? If so, how?

Yes I know it's a shit question to ask, but hey.

Re: Using expired N95 masks?

Posted: 2020-03-19 07:07pm
by madd0ct0r
Apart from inhaling birs of foam - my fear would be the degraded foam in the mask means you do not get a good seal anymore

Re: Using expired N95 masks?

Posted: 2020-03-19 07:36pm
by Shroom Man 777
madd0ct0r wrote:
2020-03-19 07:07pm
Apart from inhaling birs of foam - my fear would be the degraded foam in the mask means you do not get a good seal anymore
Yeah the shitty seal is really shitty, increases risks. I'm trying to remove the particles with tape. Otherwise I could layer it with a normal mask or even tissue paper just to block the foams.

Re: Using expired N95 masks?

Posted: 2020-03-20 08:25am
by GuppyShark
Next time I hit up my local supply store I'll see what their current stocks are.

Australians have bought up masks pretty massively after the bushfires and now corona, but the last time I went to my local store they actually had a healthy stock.

If they have some I'll grab them for you then DM you, I should be able to have them shipped to your workplace. Gratis if it's for your personal supply.

EDIT: I'm going to check tomorrow morning to see what the stock is like at my local store although I don't know how long the shipping will take time to arrange.

Re: Using expired N95 masks?

Posted: 2020-03-20 10:14am
by Mr Bean
So personal experience with N95 masks, they can be made out of a number of materials, the reason why they expire is only about four reasons and depending on what it is they can still be used.

A-The lining degrades to the point the filtration no longer is effective, unless they are made out of natural materials this is the least likely thing with an N95 mask, unless it's made of natural materials this almost never happens.

B-Rigidity loss due to moisture buildup or simple poor storage (Getting smooshed) this one is easy to ID by eye, you can tell if someone sat on a mask or it feels all lose on your face

C-Tension loss from the straps, another easy one to ID by eye if the strap don't pull on your face and are easy to shift they have degraded, to use the mask your going to have to replace them (A good 90/100 this is what you see in old masks)

D- Colony growth, another improper storage one, if the masks have gotten wet and something else (A mold for example) has started growing on them

TL:DR the only thing that can expire is natural material made N95 masks, good old Polyurethane and Polyester masks can last for decades EXCEPT for the Tension loss, you can replace those and re-use the mask but proper face seal is required for them to have the desired effect.

Re: Using expired N95 masks?

Posted: 2020-03-20 12:30pm
by madd0ct0r
Mr Bean wrote:
2020-03-20 10:14am
So personal experience with N95 masks, they can be made out of a number of materials, the reason why they expire is only about four reasons and depending on what it is they can still be used.

A-The lining degrades to the point the filtration no longer is effective, unless they are made out of natural materials this is the least likely thing with an N95 mask, unless it's made of natural materials this almost never happens.

B-Rigidity loss due to moisture buildup or simple poor storage (Getting smooshed) this one is easy to ID by eye, you can tell if someone sat on a mask or it feels all lose on your face

C-Tension loss from the straps, another easy one to ID by eye if the strap don't pull on your face and are easy to shift they have degraded, to use the mask your going to have to replace them (A good 90/100 this is what you see in old masks)

D- Colony growth, another improper storage one, if the masks have gotten wet and something else (A mold for example) has started growing on them

TL:DR the only thing that can expire is natural material made N95 masks, good old Polyurethane and Polyester masks can last for decades EXCEPT for the Tension loss, you can replace those and re-use the mask but proper face seal is required for them to have the desired effect.
Uv degradation and long term brittleness of glues between layers are the other two.

Re: Using expired N95 masks?

Posted: 2020-03-20 12:43pm
by Mr Bean
madd0ct0r wrote:
2020-03-20 12:30pm


Uv degradation and long term brittleness of glues between layers are the other two.
I'd group UV degradation in there with poor storage since exposing your PPE to direct sunlight or other UV sources normally means your improperly storing it. Glue brittleness I've yet to see in person myself but have heard off again I look back to materials on that.

Source for all this-I have been in the past a Safety Manager and am currently a second to the current one at my new position which means a lot of inventory control and inspection in multiple plants and multiple areas.

Re: Using expired N95 masks?

Posted: 2020-03-20 02:57pm
by madd0ct0r
Mr Bean wrote:
2020-03-20 12:43pm
madd0ct0r wrote:
2020-03-20 12:30pm


Uv degradation and long term brittleness of glues between layers are the other two.
I'd group UV degradation in there with poor storage since exposing your PPE to direct sunlight or other UV sources normally means your improperly storing it. Glue brittleness I've yet to see in person myself but have heard off again I look back to materials on that.

Source for all this-I have been in the past a Safety Manager and am currently a second to the current one at my new position which means a lot of inventory control and inspection in multiple plants and multiple areas.
I was thinking about the foam degradation. Something made it brittle enough to disintegrate like that

Re: Using expired N95 masks?

Posted: 2020-03-21 10:29pm
by GuppyShark
GuppyShark wrote:
2020-03-20 08:25am
Next time I hit up my local supply store I'll see what their current stocks are.

Australians have bought up masks pretty massively after the bushfires and now corona, but the last time I went to my local store they actually had a healthy stock.

If they have some I'll grab them for you then DM you, I should be able to have them shipped to your workplace. Gratis if it's for your personal supply.

EDIT: I'm going to check tomorrow morning to see what the stock is like at my local store although I don't know how long the shipping will take time to arrange.
The shelves were stripped bare. As of today there are only 67 cases in my state so this irrational panic buying.

Re: Using expired N95 masks?

Posted: 2020-03-22 09:44pm
by Knife
Considering the recent study shows home made masks are 15-57% viable, I'd say a flawed N95 (as long as you don't have harmful organisms growing in it) wouldn't be any worse that a bandana.

Would I wear an expired mask over normal mask? No. Would I wear an expired mask over nothing? Probably.