Misconceptions about RPE (Respiratory Protective Equipment)

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Jelly

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Having noticed a somewhat contentious thread about this topic, and having some practical experience of both specifying and using RPE I'd like to address some misconceptions.

1 - Powered Air Purifying Respirators (PAPR) are somehow "better protection" than unpowered alternatives:

First off both Tight-Fitting Facepieces and PAPR are quantifiably better than the common non-woven fabric "dust masks", they're generally also more comfortable to wear for extended periods.
This is an understandable misconception, but is 100% wrong.​
All RPE is given an "Assigned Protection Factor" (APF) based on a combination of their design characteristics, operating method, and physical testing of the masks conducted by organisations like BSI or TUV.​
The Trend Airshield Pro headtop only PAPR widely used in the woodturning fraternity has an APF of 20. The 3M Versaflo and Jupiter belt-mounted PAPR systems much favoured by welders and metalworkers (largely because 3M's Speedglas range is the defacto gold-standard of welding headgear), has an APF of between 20 and 40 depending on which headtop is selected to go with it.​
By contrast a Scott Promask, "tight fitting full face-piece" used as a "negative pressure filtering respirator", achieves an APF of 40, and the widely used 3M 7000 Series half face mask achieves an APF of between 10 and 20.​
Both Tight-Fitting Facepieces and PAPR are quantifiably better than the common non-woven fabric "dust masks", they're generally also more comfortable.
So there's nothing to support the assertion that a PAPR offers superior protection to a tight-fitting filtering facepiece, (in fact the opposite can be true). filtering facepieces are far cheaper, more reliable and generally wearable enough to use over a full working day (unless you're unfortunate enough to have a pre-existing respiratory condition).​
If you want to get better than that you need a supplied air system, and if you have a genuine need for that level of protection, then you should probably be paying someone to advise you on exactly what to use.

2 - All RPE is created equal:
The above point demonstrated that depending how you set it up, the same item of RPE can deliver greater or lesser levels of protection, and the same goes for different manufacturer's designs.​
It's really important to correctly identify the hazard, identify the level of exposure and then select appropriate RPE and (where applicable) filters if you want it to work properly, yes it can be complex, but there's plenty of guidance out there including the HSE's excellent HSG53 guidance document available to download free.​
3 - Reusable RPE is maintenance free compared to dust masks.
Speaking of filters, it's critically important to change the filters regularly, this is generally every 1 to 3 months from opening the filter packet, or the maximum level of usage time specified by the manufacturer, whichever comes first.​
I've seen lots of non-professional users of RPE (and more professional users than I'd care to mention) not giving due consideration to this factor.​
To be entirely clear:​
  • If you use the filter past it's intended life, it will not fully protect you,
  • If you use a filter for an excessive length of time beyond its design life, not only will it not protect you, but it's likely increasing your exposure levels to hazardous dust, because it's still capturing the coarse dust which would normally irritate your respiratory tract, and only letting the very fine dust which represents a greater health hazard through, only now you're not getting any warning signs as to your exposure.
You should also be having it serviced and tested (or at least be inspecting and servicing it yourself), every 3-6 months. The elastomeric components which make the valves and seals work can wear out quicker than you think compromising function, and with non-tight fitting PAPR headtops with a neck seal, the join to the visor can become worn and reduce air-tightness to the point that the mask no longer offers effective protection due to reduced air-flow in critical regions of the face, or a different air path through the apparatus.​
4 - Using RPE is a good solution to airborne dust:
It's a tolerable solution, though in fairness for some scenarios this assessment might be upgraded to "adequate at best".
The HSE has been abundantly clear that "Engineering Controls" should always be considered first, and I fully agree with them, you can't accidentally expose yourself to a problem that isn't there in the first place.
PPE (and by extension RPE) should always the last line of protection against hazards to health, it's also generally an expensive (in the long run) compromise compared to addressing the issues at source.​
Rather than spending money on RPE and Filters, could you actually eliminate dust altogether by using different tools and working practices? Or reduce the airborne dust to acceptable levels, say by using an extractor which isn't vented inside your workspace, / HEPA vacuum cleaner closely coupled with the source of the dust?​
It's hard to envisage all scenarios, but my guess is that the answer to this is mostly "Yes, but..." followed by some version of "I don't want to/can't think how to/it would be awkward/this is a hobby, etc." which is totally fine, it's your life at the end of the day... But don't kid yourself, you're not doing a good job managing the risk if you ignore these options and jump straight to RPE.
 

Sorry!

FWIW you'll probably still like your new Airshield Pro, especially if you plan to wear it for long periods of time; and it will be offering good protection, as an APF of 20 is more than adequate for any hazards you're reasonably likely to encounter in a woodworking environment (as long as the right filter is installed, and you're changing them as per the manufacturer's recommendation).

If you're upgrading from using a disposable dust-mask under a visor (I've always found this to be unsettlingly humid around the face) it will be a revelation!

I wouldn't choose one personally because I find the weight and bulk on my head really unpleasant, but given "the original" dust-helmet (the RACAL, now 3M Airstream) has been in production largely un-altered for over 30 years now, it's clear that there are a whole bunch of people who do like that style enough to justify ongoing production.
 
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Thank you for your very kind and considerate post.

It will be a revelation. Especially in my 120sft workshop which gets kind of warm, and ive an imbalance where i overheat really easily.
 
workshop which gets kind of warm

:sick: ←[Green with envy]

I'm having to put a great deal of time and effort into getting my workshop sufficiently well insulated to remain at an acceptable temperature, so that sounds like a nice problem to have from here.
 
:sick: ←[Green with envy]

I'm having to put a great deal of time and effort into getting my workshop sufficiently well insulated to remain at an acceptable temperature, so that sounds like a nice problem to have from here.
:D I've worked on both ends of the sppectrum, being a butcher. In supermarkets and most wholesale the average temp is 2c deg, and even one shop insisted on having the front door open throughout the year - claimed it was more welcoming, but thats as maybe when its -1 in the front shop. The workroom is in the house so ive the central heating should it get too cold, but its the opposite problem trying to keep it cool in summer.
 
Interesting post.
Strongly agree with dust elimination/extraction at source.
I think fit is the vitally important factor that makes all the difference to this choice.
If a mask is too uncomfortable to wear when tightened up enough not to leak, it's of little or no use.

Spectacles and beards complicate things.
Heavy headgear is uncomfortable for some.

Shame it isn't easier to audition all the kit on the market to find the one that DOES fit.
So far i've bought GVS, Trend stealth, 3M, Sundstrom and all feel OK for a short time. Only the Sundstrom half mask is bearable for over 30mins yet is killing the bridge of my nose after a 2hr spray painting session.
 
Interesting post.
Strongly agree with dust elimination/extraction at source.
I think fit is the vitally important factor that makes all the difference to this choice.
If a mask is too uncomfortable to wear when tightened up enough not to leak, it's of little or no use.

Spectacles and beards complicate things.
Heavy headgear is uncomfortable for some.

Shame it isn't easier to audition all the kit on the market to find the one that DOES fit.
So far i've bought GVS, Trend stealth, 3M, Sundstrom and all feel OK for a short time. Only the Sundstrom half mask is bearable for over 30mins yet is killing the bridge of my nose after a 2hr spray painting session.

On the fit thing, have you tried a full face mask?

I have a Scott Vision 1000 full face mask as my main work issue mask, (and have used Scott and 3M masks on non-personal BA sets) and find it actually very comfortable, compared to most other options I've used, definitely more comfortable than half masks.

If you speak to a local ARCO branch they may be able to arrange for you to trial fit a number of masks to see which is right for you, and sort out a corrective lens insert too (basically a frame you can get an optician to put cheap lenses in which clips inside the mask so it doesn't rest on your nose) if required.

If you're using frequently for spraying, the additional comfort may well justify the £100 or so investment.
 
My friend and I picture the end game as a bigger better compressor sited outdoors and able to run the gun and a couple of air fed head pieces. With that we will have the added option of spraying 2 pack.
I get that a properly fitted negative pressure mask can be highly rated but do see positive pressure as more foolproof in case the mask doesn't seal perfectly.
Until then, your post is a good challenge to dump some unconscious biasses and at least try a full mask which I never have used before.
Thanks :)
 
The 3M versiflo can be used in various environments from chemical to asbestos and dust depending on which filter is used. Obviously a filter cartridge for dealing with harmful chemicals will cost £1OO.
I have used close fitting masks like sundstrom for wood dust but found them uncomfortable after a couple of hrs. I still use one for spraying but with the appropriate filters.
I mess about with lumps of old machinery as well as wood so I am very aware of things that will cause harm like lead paints and fillers.
 
I have the Versaflo, but a TR3xx not the latest generation TR-6xx. Mine only has dust filters and a type rated for "nuisance" chemical odours available which I assume rules it out for spraying solved based enamels. The newer model takes a better chemical filter but that was well past my budget :) These PAPR sets are not cheap !
 
I bought my first Racal Airstream respirator back in 1984. Working in the boat trade doing general boat repairs both wood & grp dust was a constant issue, many of the timbers we used were not healthy & grinding fibreglass is the poxiest job in the world.
Extraction was often used but couldnt control the dust adequately. I wore that first Airstream out & bought another. That one wore out & i was lucky enough to pick up three little used ones so i have an adequate supply of spares. As far as i know 3M discontinued the Airstream a few years back & many of the parts are no longer available.
When i see the state of the filters & what they have sucked in i do wonder what my lungs would have been like without wearing it all those years.
When i worked in the boat trade very few men bothered with anything unless it was a nuisance dust mask, the building trade is the same, how many times do you see someone driving a paddy's motorbike, cutting stone with dust flying everywhere?
 
FWIW you'll probably still like your new Airshield Pro, especially if you plan to wear it for long periods of time ...
I wouldn't choose one personally because I find the weight and bulk on my head really unpleasant ...
Wood turners like the Airshield because of the protection it gives against flying billets.
 
Wood turners like the Airshield because of the protection it gives against flying billets.
I certainly wouldn't advise woodturning without a face-shield!

Most other PAPR options and all Full Face options also offer protection to EN166 1-B* or better, but don't put as much weight/bulk on your head, hence my preference.

Having had ample opportunity to try just about every RPE system on the market at this point in my professional life, I'm comfortable saying the Head-Top only type PAPR systems aren't for me, but that's not to say they're not a good fit for others.

*The "medium impact" standard for eye protection, indicating the safety device is proof against a 6mm ball bearing hitting it at 120m/s (269mph)
 
If you use a filter for an excessive length of time beyond its design life, not only will it not protect you, but it's likely increasing your exposure levels to hazardous dust, because it's still capturing the coarse dust which would normally irritate your respiratory tract, and only letting the very fine dust
I'm certainly no expert so this is only my thinking but I can't see how using a filter beyond it's expiration date would allow it to allow more fine dust through? I would have thought if anything over use of a filter will just clog the filter and make breathing more difficult.

This article seems to confirm my assumption Does HEPA Filter Efficiency Decrease Over Time and With Age? – Smart Air Knowledge Base

My understanding with expiration dates is for chemical filters e.g. activated charcoal as they will gradually absorb things out of the air until they no longer work.

I can't see how a mechanical filter would expire just by being exposed to air?
 
Many never think/consider storage when not using "anti" dust items.

One example was on Paul Sellers YouTube Show Hes off to Butcher some wood/MDF etc Under Bandsaw so puts on his paper/fibre/whatever? Mush mask which oddly has been hung up on a nail/screw by machine since Noah left it behind when fitting out the Ark!
So had a constant wafting of fine saw dust particles plus other dusts of? then once chopped up said woody stuff hangs it back up on said nail/screw?.
Now dust/fine particles are still airborne as they don't immediately stop/fall to the floor as press Red button so mask is not only being contaminated from breathing in and out but also the insides are from hanging there exposed to airborne poop.

Friend when i said about it bleated he knows what doing hes been doing woodwork since Noah gave him a Woden plane!

After knowing quite a few that have succumbed to Lung diseases four was in motor trade Asbestos took at least two my best friend was a mixture of that.Lead from old panelworking.body filler.spray painting>.Another worked steaming out empty tankers.
Friend school mates dad got asbestos not from working with stuff but they hired out the trailer units and dropped down dead on holiday found in postmortem!

When was doing welding/Fabrication always put my googles and welding head shield away in bags/boxes as soon as took off.

Those sealable boxes like tupperware cost little compared to lungs store in them and new filters etc in another as dust gets everywhere.
 
Many never think/consider storage when not using "anti" dust items.
I agree with your points on storage to avoid contamination. I always take mine back in the house and am careful to avoid dust from the strap falling into the mask. When i come to use it again I'll normally run my finger around the inside to catch any bits and then blow through a couple of times to hopefully blow out any bits i've missed before putting it on.
 
Great post, agree totally with what you have said that engineering controls should always come first (have a career in filter design also). It has always surprised me more don't put dust control higher on the buying list for new tools, too many other factors seem to come forward before it goes down the route of brand fans / haters that come out of the woodwork literally. One has only got to look at the successful aftermarket mods for dust collection to realise that not all the tools are created equal!
 
I'm certainly no expert so this is only my thinking but I can't see how using a filter beyond it's expiration date would allow it to allow more fine dust through? I would have thought if anything over use of a filter will just clog the filter and make breathing more difficult.

This article seems to confirm my assumption Does HEPA Filter Efficiency Decrease Over Time and With Age? – Smart Air Knowledge Base

My understanding with expiration dates is for chemical filters e.g. activated charcoal as they will gradually absorb things out of the air until they no longer work.

I can't see how a mechanical filter would expire just by being exposed to air?
I'd be interested if the OP or someone else with experience could comment on this. Everything seems logical.
 
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