How often do you have to change them?
1139749
I have used the same mask several times when I've worn for a short period (I keep it on a ziploc bag). Otherwise, I would use it once if worn all day. You can also tell if they get dirty. Hope this helps.
1139750
Its depends on what environment your using them in if your using it just for everyday use to avoid breathing germs or spreading them your probably good for a couple of days if your in hazardous fumes you may need to change daily or even more than once a day depending on what exactly your working in
1139751
My husband has copd and he only uses them when the air quality is bad and he has to go outside. He uses one only one time.
973752
to be honest I am not sure we have had for a little over a year and I have never had to change them...prob played with 4x a month
569543
eventually yes, you are going to replace them depending how often and rough you are with them.
1402452
I've never really paid attention, but I have to change them two or three times while I have it out, which is usually about May to October.
588250
They last quite awhile actually. I change mine out weekly, even though I never see more than minor wear on them.
2095672
It depends on how many people you have in your house. If you have a full family of 4 or 5 or more, once a year. We have 2, I replace every other year.
156747
I tend to change mine about 2-3 times a year and I don't use the extra functions all the time
1884482
We've only been using them since March...sporadically. So, we've never changed them.
2247771
My wife and I only have to change it every 6 months, I'd say 4-6 months would be your average. Works great BTW
2024826
You dont have to but it is a good time to change them if you havent ; or they are due.
1171463
I change mine about every 6 months, but I only use it at work. It doesn't get everyday or all day use.
2195242
I change mine every 6 months. I have pets. You may be able to go longer if you don't have pets.
128259
I've changed mine when needed, around 6-12 months, and it does make a difference.
474827
I change when I start using them when the house starts to dry out, the reason to change them is because they will start getting mold/mildew on them and start to stink.
1621248
It depends on how often you change diapers, I usually change it every week.
914149
As far as I know, they are pretty much disposable. I haven't needed to change it. However I don't think you can.
1969914
I've had it over a year. I use it at least once a day, usually more. Have not changed them yet.