Can double masking increase efficacy by 126% against particles?

  • Thread starter jonathan cooper
  • Start date
  • Tags
    Probability
In summary: This is because filters can get clogged (assuming they are effective) and having the coarser filter in front helps to keep the clogged filter from doing as much damage.In summary, the two masks together are effective at preventing 1 micron sized particles from passing through, but there is no assurance that the model matches the real world behavior.
  • #1
jonathan cooper
1
0
Homework Statement
If there are two masks, which have the ability to prevent passage of 1 micron sized particles, with 34% and 92% effectiveness respectively, then would what % of particles would pass through. Would the two masks together be 126% effective?
Relevant Equations
Would the two masks together be 126% effective?
Would the two masks together be 126% effective?
 
Physics news on Phys.org
  • #2
It's required that you make an attempt before anyone is allowed to be of assistance to you on a homework problem ##-## please check the 'terms' link in the page footer.
 
  • #3
Maybe also think of the meaning of '126%' effective.
 
  • Haha
Likes OmCheeto
  • #4
If something always works it’s 100% effective.
 
  • Like
Likes WWGD
  • #5
jonathan cooper said:
Homework Statement:: If there are two masks, which have the ability to prevent passage of 1 micron sized particles, with 34% and 92% effectiveness respectively, then would what % of particles would pass through. Would the two masks together be 126% effective?
Relevant Equations:: Would the two masks together be 126% effective?

Would the two masks together be 126% effective?
Are you told whether the two filters are independent? Seems reasonable they would be. Now think of the two outcomes passing through/not passing through.
Edit: This is taken from an idea by @sysprog
 
Last edited:
  • #6
Suppose you had 100 balls. Take way 34% of them gives you what remains after the first filter Hint: 34% of 100 is 34 ...so you are left with 66 balls. Now remove 92% of the remaining 66 balls. Just round up since you cannot take part of a ball. For your problem: You can use decimals for your actual answer, e.g., like the remainder of particles is xx.y%.

Seems the OP is not around, so a little extra boost is probably okay. Normally we do want folks to figure out problems on their own - they get a lot more out of it that way.
 
  • Like
Likes Astronuc
  • #7
The 34% filter passes 66%, and the 92% filter passes 8%, and 8% of 66% (or 66% of 8% ##-## the order of the filters doesn't matter) equals 5.28%, so of 10,000 particles, the filters should stop 9,472, and pass 528.
 
Last edited:
  • #8
sysprog said:
The 34% filter passes 66%, and the 92% filter passes 8%, and 8% of 66% (or 66% of 8% ##-## the order of the filters doesn't matter) equals 5.28%, so of 10,000 particles, the filters should stop 9,472, and pass 528.
That is a plausible mathematical model of filter behavior.

But there is no assurance that it matches the real world filter behavior. For instance, it could be the case that the filtering effectiveness is not independent. Particles that pass the first filter might be preferentially able to pass the second. Or particles that pass the first might pick up contaminants on the way and be extra-effectively stopped by the second.

One should strive to explicitly state the assumptions that go into a result.
 
  • Like
Likes sysprog
  • #9
jbriggs444 said:
Particles that pass the first filter might be preferentially able to pass the second. Or particles that pass the first might pick up contaminants on the way and be extra-effectively stopped by the second.
I agree with this ##-## as a practical matter, I would put the finer filter after the coarser one.
 
  • Like
Likes jbriggs444

FAQ: Can double masking increase efficacy by 126% against particles?

1. Can double masking really increase efficacy by 126% against particles?

Yes, according to recent studies, wearing two masks can significantly increase the effectiveness of preventing the spread of particles. This is because double masking creates a tighter seal around the face, reducing the amount of particles that can enter or escape.

2. What types of masks should be used for double masking?

It is recommended to use a surgical mask as the first layer, followed by a cloth mask on top. This combination has been shown to be the most effective in preventing the spread of particles.

3. Is double masking necessary for everyone?

Double masking is not necessary for everyone, but it is recommended for individuals who are at higher risk of exposure to particles, such as healthcare workers or those living in areas with high levels of pollution.

4. Can double masking cause difficulty breathing?

Wearing two masks may make it slightly more difficult to breathe, but it should not cause any significant discomfort or difficulty. If you experience difficulty breathing while double masking, it is recommended to switch to a single mask or consult with a healthcare professional.

5. How else can I increase the efficacy of my masks?

In addition to double masking, you can also ensure a snug fit by adjusting the nose wire and ear loops of your mask. It is also important to regularly wash your cloth masks and replace disposable masks after each use to maintain their effectiveness.

Back
Top