Thread: When to replace P2/3 cartridges?

What are you protecting yourself against?

check this 3M brochure for some info
http://multimedia.3m.com/mws/media/7...on%20Guide.pdf

Establishing a cartridge change schedule requires knowledge of thecontaminant(s) and the levels to which you are exposed. You may be able tomeasure your own levels using a personal sampling device. This will provide somepreliminary measurements which can be used to establish a change schedule.

To determine the schedule of changes when using cartridges with organic vapours there is a piece of software available from 3M (see PPE Safety Solutions : 3M Safety Product Catalog:Reusable Respirators & Parts)

To use the software requires you to be able to answer a bunch of questions like
Level of contamination exposure in ppm
What 3M Cartridge are u using?
How humid is the environment? (
What temperature is the work environment?
How strenuous will the work be?

I tried it for something trivial like 500 ppm of turps and it could not calculate the schedule for this.

Not very helpful really.

Just dust. Also, I meant P1 and P2, not P3, didn't check before I typed it

Originally Posted by elanjacobs

Just dust. Also, I meant P1 and P2, not P3, didn't check before I typed it

I assume wood dust?

If so, and provided you feel no resistance, then, unlike for organic vapours, there is no need to replace the cartridges.
As cartridges get more clogged they actually get more efficient at removing fine dust.
However, as they get more clogged, it they are used in a half face style respirator, then there is a greater chance that dusty air will be drawn around the edges of the mask.
On a full face respirator the amount of fresh air available will be reduced and that too has its down side.

The Triton full face respirator comes with a neat simple flow tube that is fitted to the pump hose in place of the respirator.
The flow meter is just a small ping pong like ball inside a clear plastic tube. The tube is pushed and held vertically onto the end of the hose attached to the running air pump.

The pump is switched on and if the ball reaches the black circle as marked on the outside of the top of the tube the pre filter and cartridges are OK - if not clean the pre-filter and test and if still not lock replace the cartridges. It also indirectly tells you if the batteries are running down and need charging.
IMG_7069.jpg

Ir's OK to use like this but I also haven't used the respirator for about 9 months so it could just be the batteries need charging
IMG_7070.jpg

Its easy enough to carry the flow tube around in your pocket and test periodically as needed.

I haven't needed to replace the cartridges in the Triton for the 8 years I have had the respirator.
Some of this is because I am very careful about cleaning the pre filter after every half hour or so of use.
I used to use the respirator about once a week but since I got good dust extraction in 2011 I only use it 2/3 times a year.

If you are interested I can measure the flow and/or pressure loss across the filter.

BTW I would not use a P1 mask for wood dust as they are just too inefficient at removing fine dust.

Yep, just wood dust. I'm using one of these: https://www.carbatec.com.au/health-s...ered-dust-mask
The blurb says it filters to 0.4 micron, dunno how true it is...
The cartridges are P1, I'd get P2 if they were available

Originally Posted by elanjacobs

Yep, just wood dust. I'm using one of these: https://www.carbatec.com.au/health-s...ered-dust-mask
The blurb says it filters to 0.4 micron, dunno how true it is...
The cartridges are P1, I'd get P2 if they were available

I will have to retract my comment on the P1 cartridge.
I looked up my testing for P1 and found they were the same (>99.5%) efficiency down to 0.5 microns and only between 0.3 and 0.5 microns did the P2 outperform the P1 by about 1%.

I won't go into what I think of masks as I'm sure you have heard it all before.
If folks have no choice but to wear a mask in low effort woodworking situations (i.e. not thicknessing heavy planks) I recommend a certified medical disposable mask.
These medical masks are as efficient as P2 rated cartridges, lightweight and comfortable, they have very low resistance so low leakage rates around the sides, and cheap enough to use a new one every day or even half day.

Anyway if you want me to test the flow rate through one of your used filters I am happy to do that and I can compare the flow rate to a new p1 filter I nought for testing purposes..

Thanks for the offer, I'll try to remember next time I change it.
I only use it when I'm hand-sanding or spending lots of time on the linisher/freehand drum sander. I'm working on getting the pipes on that bumped up from 3" to something that's actually useful; I get as close as I can to the hood which seems to help a bit. Maybe when we buy a new extractor I can convince the boss to redo all the ductwork, but it's gonna be a hard sell; $25-30k just for the extractor is already a big investment

I had the air flow measuring gear out this morning and managed to measure the air flow from the fully charged Triton respirator.

The flow is 2.9 L/s or 174 L/min.

Note this is for two P2 cartridges in parallel.

I realise this does not help the OP but it may help others to know what is a typical flow rate.

I find the air flow sufficient for all but high effort work and if it gets over about 35º it gets a bit claustrophobic.