Hey Stuart. Best to start with WorkSafe's Fit Testing advice provided in this link.

I will resist providing any steer on the testing methods as there is sometimes a tendency to get the fit testing and fit checking terminology muddled, and the differences in qualative and quanttive methods.

I will go out on a limb though and state that any tight-fitting mask will not be effective if the seal is compromised in any way, including the presence of stubble.

Best to check that any mask purchase meets the requirement of AS/NZS 1716, although other standards are recognised by WorkSafe e.g. NIOSH, EN149, GB2626. Better still, purchase these items through a reputable supplier.

No offence @Stuart Keer-Keer but have you done any due diligence?
I get the impression that rather than asking for clarity about a chapter or two, you want information about the entire book because you have only read the dust jacket flap.

Quick research indicates that Clean Space masks clearly state on their website what type of respirator they produce. IMHO, generally, 3M are the goto organisation regarding these types of respirators.

Fit testing and face seals are two methods used for ensuring a certain type of respirator is both fit for purpose and fitted corrected. While CleanSpace Respirators (to give them their correct name) do reference fit-testing and the appropriate AS/NZS standard, a PAPR works in a different fashion to a respirator that requires fit-testing and face seal checks.

When wearing a respirator, air comes in from somewhere. And it exists somewhere also. Knowing how the air enters and exists a respirator can assist determining whether fit testing is required.

Equally, the purpose for it's use as well as the size of the budget will determine the type of respirator. For me, it's no different than deciding whether to purchase standard LED bulbs or convert the house using smart bulbs. It depends on what I want to do and how much money I have.

So going back to the beginning, I suggest some research - 3M, Euromarc, Honeywell, GVS-rpb - and then have a discussion.

My 2 cents worth.

My apologies my question was not clear enough.

The question is has anyone any views on testing the Clean Space masks, if so do they do it in the powered on mode or power off mode?

Background

Workers must pass a respirator fit test before they first start wearing a tight fitting respirator. Fit testing measures the effectiveness of the seal between the respirator and the wearers face. It is required for all tight fitting respirators, including:-

• lf face disposable
• half face reusable
• full face reusable
• tight

fitting powered air purifying respirators (PAPR)

Hood Type PAPR
It is not required for hood type air purifying respirators (PAPR). These devices work by over supply of air so the wearer is in positive pressure.

Tight fitting PAPR Operation
The tight fitting (PAPR) work opening the demand valve to supply air to the wearer when the positive pressure inside the facepeice decreases to a present minimum.

Testing of Tight Fitting PAPR
The requirement for testing tight fitting PAPR is to in the negative pressure mode. (fit tested as negative pressure air respirators) This means the powered unit is turned off. A tight fitting mask is not suitable for people with beards.

Clean Space how it works
With the Clean space tight fitting PAPR masks they work by oversupply of air. They maintain as it is an oversupply of air the fit testing can be done in the powered on mode.

Beards and Clean Space Masks
Clean Space advocate as their tight fitting masks work on a positive pressure mode so can be worn with people with beards.

What masks can bearded people wear?
PAPR with a hood.

Hi Stuart,
These are my thoughts.

The term "tight fitting respirator" is commonly associated with negative pressure respirators where air is drawn by the wearer inhaling through a filter usually attached directly to the respirator. This requires the respirator to fit the face (in the case of half face respirators) or head (in the case of a full face respirator) so contaminants cannot be inhaled by the wearer.

Ensuring an airtight face seal while wearing this type of respirator is essential. Fit-testing is the method to ensure the respirator fits the face or head of the wearer and seals under simulated conditions. A face seal is the method to ensure the wearer has donned the respirator prior to use and is airtight sealed to the face or head or the wearer.

PAPR respirators work on the principle of supplying air at higher pressure inside the respirator than the surrounding environment therefore expelling any contaminants so they cannot be inhaled by the wearer. Usually the air is expelled around the side of the head, face and chin areas from a hood or full face mask.

Now you stated,
"Beards and Clean Space Masks
Clean Space advocate as their tight fitting masks work on a positive pressure mode so can be worn with people with beards."

A question here. How can a tight fitting respirator based on PAPR become a negative pressure respirator and have an adequate face seal for a person with a beard?

I base the question on this.
A PAPR has air provided to the wearer via a mechanically filtered pump or an external air supply, so how when these items are switched off, can the wearer inhale air either when fit-testing or when ensuring an airtight face seal.

So these are my views regarding your question which I'll repeat:
"The question is has anyone any views on testing the Clean Space masks, if so do they do it in the powered on mode or power off mode?"

IMHO your question should be directed to the manufacturer.
Cheers.

A question here. How can a tight fitting respirator based on PAPR become a negative pressure respirator and have an adequate face seal for a person with a beard? — KeithH

It will not have an adequate seal.. Tight fitting respirators require a seal to work. So no beards. Refer to the CDC document below, that stipulates tight fitting PAPR respirators require fit testing. If you have a beard on a tight fitting powered air purifying respirator. (PAPR) you are not expected to pass a fit test.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.cdc.gov/niosh/docs/2018-176/pdfs/2018-176.pdf

A PAPR has air provided to the wearer via a mechanically filtered pump or an external air supply, so how when these items are switched off, can the wearer inhale air either when fit-testing or when ensuring an airtight face seal. — KeithH

The wearer draws air through the filter on the PAPR system. It becomes just like negative air respirators.

If the facepiece is used in the PAPR mode, it can be converted into the negative pressure mode by simply not turning on the motor blower assembly. This is a quote from the below 3 M document.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://multimedia.3m.com/mws/media/9461O/fit-testing-tight-fitting-ppr-161-technical-bulletin.pdf

We have recently come across Clean space masks which are powered masks that resemble the fittings on the close fitting powered respirators. — Stuart Keer-Keer

I think the key detail that is getting confused here is that the CleanSpace RPE "resembles" a close/tight fitting negative pressure RPE.
The CleanSpace RPE are being supplied as a Powered Air Purifying Respirator (PAPR), not a negative pressure respirator. Treat it as such when developing your RPE procedures.

All respirators (PAPR and NP) are required to fit the user, e.g. selecting the correct size (and sometimes brand/model), and confirming it fits as per the manufacturers instructions/requirements.
Negative Pressure RPE are also required to check that the seal between the face and mask is not leaking to confirm that incoming air is passing through the filters and not bypassing through a leak in the seal. PAPR do no require this as their design ensures that air is drawn through the filters (and will blow out through any gaps between the RPE and the users face/body).

However critical for PAPR is to ensure that the are working correctly when in use, such as making sure that;

• Masks / hoods fit as per the manufacturers requirements - the initial (and periodic) fit-check above
• Fans operate continuously (batteries, breakdowns) - periodic maintenance and incident reporting
• Filters are changed out when required - filter replacement program.

So to answer your question of "The question is has anyone any views on testing the Clean Space masks, if so do they do it in the powered on mode or power off mode?"
They are designed as PAPR, so issue them as PAPR.
Asking if you should test them powered on or off is somewhat illogical because this has no bearing on if the mask (i.e. the shape/size) fits the users face - so I guess my answer is both, do a general fit with the power off to make sure the mask is comfortable, but also power on to check for any large leaks or disruptive leaks (such as around the bridge of the nose directing a flow of air into the eyes). Make sure they fit as per the manufacturers instructions/requirements.
But critically if you are using PAPR make sure your RPE procedures manage the risks associated with PAPR. And finally don't assume that just because they look like a negative pressure respirator that they can continue to be used as a negative pressure respirator if the batteries die or the fans break down.
Edit: Added references:
Respiratory Protection for Workers with Facial Hair - Australia
Note: CleanSpace actually recommends in the (Australian specific) guidance for demonstrating compliance with employer’s legal obligations a "protection factor" test following the US OSHA regulations (rather than the AS/NZS standard) in power-on mode. This conflicts with OSHA 1910:134 as the fit testing requirements specifically states to test in power off mode, however the testing is only required for tight fitting masks (negative or positive pressure). Therefore the way I would interpret CleanSpace's guidelines is that while OSHA 1910:134 fit testing is not legally required for the CleanSpace respirators (as they are not consider to be tight-fitting masks that rely on the seal between the mask and face to function properly), a fit test should be completed to confirm the respirator does provide the employee with the required level of protection (i.e. Protection Factor / required reduction in airborne contamination)... i.e. ass-covering if I am being facetious.
PAPR typically are assigned a Protection Factor of 50, while cleanSpaces studies have resulted in an average Workplace Protection Factor of over 8000, with the lowest ever result of 105 (i.e. the worst ever result was still twice as good as the assigned protection factor). Given the operation and CleanSpace studies data I would be comfortable forgoing the recomended "protection factor" test as long as the general fitting was being monitored for effectiveness.

A question here. How can a tight fitting respirator based on PAPR become a negative pressure respirator and have an adequate face seal for a person with a beard? — KeithH

It will not have an adequate seal.. Tight fitting respirators require a seal to work. So no beards. Refer to the CDC document below, that stipulates tight fitting PAPR respirators require fit testing. If you have a beard on a tight fitting powered air purifying respirator. (PAPR) you are not expected to pass a fit test. — Stuart Keer-Keer

I think it was a bit of a trick question - the actual answer is a PAPR can never become a negative pressure respirator, as it was not designed as a negative pressure respirator. So not matter how much a PAPR kind of looks like a negative pressure respirator, it should never be considered a negative pressure respirator and if it has stopped operating as a PAPR it should be removed from use and repaired/discarded.
Edit: Supporting info relevant to the CleanSpace respirators:
Use of CleanSpace PAPRs by workers with Facial Hair - Manufacture's Statement

A PAPR has air provided to the wearer via a mechanically filtered pump or an external air supply, so how when these items are switched off, can the wearer inhale air either when fit-testing or when ensuring an airtight face seal. — KeithH

Most (if not all) PAPR supply air via a fan and not a positive displacement pump. When the fan is not operating air can easily bypass it and still be drawn through the filters and into the mask.

From Resp-Fit:
What type of respirators are required to be fit tested?
All types of tight-fitting respirators (negative and positive pressure) must be fit tested as required by AS/NZS 1715, ISO 16975-3 and all other international RPE guidance.

This includes all disposable/filtering facepieces (FFP), reusable half face, reusable full face including those attached to a powered air purifying respirator (PAPR) or supplied air source such as SCBA cylinder and compressed airline hose.

It is commonly asked why do positive pressure tight-fitting respirators require fit testing? Generally, the assigned protection factor for these positive pressure combinations is higher than a negative pressure equivalent style facepiece. This higher assigned protection factor is based on the wearer achieving an adequate seal in addition to the positive pressure. A positive pressure respirator would be temporarily converted to be negative pressure or use a negative pressure respirator with an equivalent sealing surface to conduct the fit test.

From Resp-Fit FAQ's:
Why is it a requirement to be clean shaven when wearing a respirator? (both postive and negative pressure tight fitting facepieces)
Many studies show that the presence of facial hair between the sealing surface area and the skin can significantly reduce the expected level of protection. Many hazards of concern e.g. asbestos, silica, DPM, mould, bioaerosols are many times smaller than a single facial hair and can bypass between them. Gases and vapours can bypass between facial hair as well. A tight-fitting respirator has been selected as part of a control strategy to provide an expected level of protection. With facial hair the expected protection is not predictable or reliable.

So the answer is in the standards and methods for RPE Fit Testing (ISO16975-3, OSHA 1910.134).

All tight fitting facepieces for respiratory protective devices (RPD) including those as part of PAPR or supplied air systems are to be fit tested. They must be fit tested in a negative mode and not have anything that interferes with the seal between the facepiece and the skin such as facial hair.

A fit test not done in accordance with a recognised method or varies the method is generally considered invalid.

Cleanspace is certified as a tight fitting facepiece under AS/NZS1716. It therefore requires fit testing in a negative mode. Fit testing in the positive mode is a variation against the fit testing methods and would be considered an invalid test despite the manufacturer's claims.

See the answer from Resp-Fit website FAQs for 11 & 12 https://respfit.org.au/faqs/

Cleanspace is certified as a tight fitting facepiece under AS/NZS1716. — RPE Fit tester

CleanSpace state that their masks are not designed as tight-fitting / close-fitting RPE as they do not rely on a tight seal between the mask and the users face.

CleanSpace PAPR protection performance is not reliant on achieving a good mask seal. Annual fit testing and being clean shaven will improve a wearer’s mask fit. However, these are not required to ensure a high level of wearer respiratory protection. — Use of CleanSpace PAPRs by workers with Facial Hair - Manufacture's Statement

The CleanSpace would be considered a loose-fitting facepiece under the OSHA regulations, with an assigned protection factor of 25. This is compared with an APF of 10 for a negative pressure tight-fitting half-mask respirator, or 50 for a PAPR tight-fitting half-mask respirator. Given most will be moving from the typical negative-pressure half-mask respirators this is still a significant increase in the APF, with CleanSpaces studies showing that the actual realworld workplace protection factor will likely be even greater (at least 100 if not in the thousands).

Also it seems like the links I added above aren't working, but I'm too late to edit those posts - hopefully these links work:

Edit: Supporting info relevant to the CleanSpace respirators: — MattD2

https://cleanspacetechnology.com/documents/product-resources/STATEMENT-MANUF-MAY082023REV2.pdf

Respiratory Protection for Workers with Facial Hair - Australia — MattD2

https://cleanspacetechnology.com/documents/product-resources/Respiratory-Protection-for-Workers.pdf

Thanks for the reply MattD2,
You may want to check with WorkSafe about their position on this as I understand they require Cleanspace to be fit tested in negative mode for it to be a valid fit test.

Thanks for the reply MattD2,
You may want to check with WorkSafe about their position on this as I understand they require Cleanspace to be fit tested in negative mode for it to be a valid fit test. — RPE Fit tester

Do you have a source for that claim on WorkSafe's requirements specific to CleanSpace respirators?

I find whenever asking WorkSafe for clarification on a question like this they give the standard "you have to manage the risks" response (not to blame them as their is so much variability between individual situations that a blanket claim could be never cover them all).

Or a source that the CleanSpace RPE are certified as a tight fitting facepiece under AS/NZS1716?
I am going off the information on the CleanSpace website - which they clearly say that the facepieces do not rely on a tight seal to work properly, and that they should be fit tested with the power on.
https://cleanspacetechnology.com/documents/product-resources/Respiratory-Protection-for-Workers.pdf

From Cleanspace's website: https://cleanspacetechnology.com/faqs/
How do I know if the mask is fitted correctly?
Cleanspace is a tight fitting respirator and should be fitted so that the mask fits to the face.

Also AS/NZS1716 does not have a provision for the certification of half face loose fitting PAPR only tight fitting half face. Loose fitting under this standard requires a complete hood or helmet.

EN12942 does have a loose fitting half face category (TH) but Cleanspace is categorised as a TM which is a tight fitting face piece.

RPE standards are reasonably intricate and with the recent adoption of the ISO standards by AS/NZS we have seen two standards replaced by 31 standards. Get ready for the next 5 years of transferring over.

Also AS/NZS1716 does not have a provision for the certification of half face loose fitting PAPR only tight fitting half face. Loose fitting under this standard requires a complete hood or helmet. — RPE Fit tester

AS/NZS 1716 doesn't use the term "tight fitting", hence they also do not use the term loose fitting. The AS/NZS standard defines the terms "half facepiece" and "full facepiece" as "a close fitting device to cover the nose, mouth and chin / eyes, nose and mouth [respectively] and be secured in position by suitable means." Close fitting would be considered as resting against the face, but the standard does not specify these have to be "tight fitting" and rely on a seal between the mask and skin to function correctly. Section 3.2.1 specifies that "the assembled respirator shall provide adequate protection either by means of a facial seal or by the provision of positive pressure in the space enclosed by the respirator, or by both, to minimize the entry of ambient atmosphere."
And the facial fit tests (App. D Total Inward Leakage tests) are separated into either "non-powered filtering respirators" or "powered filtering or supplied-air respirators" - the tests are not determined on the facepiece style but the operation of the respirator. It would be expected that the CleanSpace respirators would be tested under the D4.3 test for powered filtering respirators.

Unless I have missed something in the standard that says you cannot have a PAPR with a half mask, or a half mask must minimise the entry of ambient atmosphere by means of a facial seal alone. If I have missed where it says either of these I am keen to know?

From Cleanspace's website: https://cleanspacetechnology.com/faqs/
How do I know if the mask is fitted correctly?
Cleanspace is a tight fitting respirator and should be fitted so that the mask fits to the face. — RPE Fit tester

I would consider the manufacture's statements to be a more authoritative source than a single question/answer on their FAQ page:
Use of CleanSpace PAPRs by workers with Facial Hair - Manufacture's Statement
While the user manual also instructs to complete a seal check where donning the masks, the above statement indicates this isn't primarily for safety but more likely for usability given elsewhere in the manual they state that battery life / filter life are dependent on a adequate seal (i.e. with a loose seal the fan will be constantly running on/near full power to maintain the set pressure within the facepiece).

I can see why you want to take this path, it would be awesome to have a tight fitting half face PAPR that you can wear with facial hair. it would be a great marketing point of difference. Strange that no other major RPE manufacturer make the same claim especially any that have a product with certification under EN12942 as a TM.

Personally I would only fit test tight fitting face pieces when the wearer is clean shaven and if it is a PAPR or supplied air that it is under negative conditions.

R@RPE Fit tester Thanks your clarity and explanations are fantastic.

On the post above you say all PAPR need fit testing, what about hood ones that are positive pressure?

It was my understanding these do not - what is your understanding around these?

I can see why you want to take this path, it would be awesome to have a tight fitting half face PAPR that you can wear with facial hair. it would be a great marketing point of difference. Strange that no other major RPE manufacturer make the same claim especially any that have a product with certification under EN12942 as a TM. — RPE Fit tester

There always has to be someone that is first to market with an innovative product. I would expect that most of the other RPE manufactures have been caught resting on their laurels regarding R&D of truly innovative RPE. CleanSpace's "story" webpage calls this out.

Personally I would only fit test tight fitting face pieces when the wearer is clean shaven and if it is a PAPR or supplied air that it is under negative conditions. — RPE Fit tester

And that is your opinion, but can you point to anywhere in the AS/NZS Standards or WorkSafe guidance that specifically states that a PAPR that uses a close fitting face-piece must designed and tested with the assumption that the respirator is a negative-pressure type respirator and must rely on the facial seal to prevent inward leakage. Clause 6.4.3 in AS/NZS 1715 (1994 version is all i have on hand) does include that:

Respirators incorporating close fitting facepieces rely on facial fit to prevent inward leakage of contaminants. Such respirators employing a full facepiece or half facepiece must not be used by males who are not clean shaven about the cheeks, neck and jaw. Half facepiece respirators of this type must not be used by those with moustaches where there is any chance of hair coming between the facepiece and the skin.

But also goes on to say in the same clause:

Respirators which maintain a positive pressure in the facepiece at all times provide a higher degree of protection than can be achieved with negative pressure types. Positive pressure respirators may diminish the effect of poor facial fit but will not obviate the effect of leakage caused by facial hair (see Clause 7.5). Where conservation of the air supply is important, e.g. self-contained breathing apparatus, it should be recognized that any leakage, e.g. from the facial seal, increases air consumption and decreases service time.

Given "facepiece" is only used in reference to close fitting half or full face masks (hood or head covering do not get referred to as "facepieces") The second part of the clause would somewhat clarify that the first part is referring to negative-pressure type half/full masks.
The testing regimes in App D (which are informative only) also do no specify that testing should be done so that the facepiece is worn in a "negative-pressure way", and it would be assumed that when testing the RPE is effective it would be used in the same way that it would be used "in the field" (i.e. powered on for a CleanSpace PAPR).
You also have to consider that CleanSpace released their first model in 2010 (a year after the company was founded). This is one year after AS/NZS 1715 was last revised and only 2 years before AS/NZS 1716 was revised - although nothing in the latest standard would prevent CleanSpace's RPE getting certified under AS/NZS 1716 as a PAPR without the need to rely on a facial seal. The claims made in the standards need to be considered with the knowledge and information available at the time they were written, since then CleanSpace's own studies/research has shown that their PAPR provide an adequate level of protection even when worn by those with facial hair - remember that this is research that was completed more than 10 years after the AS/NZS standards were last revised.

Irrespective of all this and what I have said before, and taking into account that legislation / Standards always lag behind innovation - the ultimate question that needs to be answered is "does the selected RPE manage the risk of working in a contaminated atmosphere so far as reasonably practicable?"
Which is why fit testing (qualitative or quantitative) is recommended to establish if the provided RPE provided the required level of protection. It is also why it should be tested as close as practical to how it will be used in the actual work environment, e.g. moving, heavy breathing from heavy workloads, talking, etc.
If the CleanSpace PAPR can be shown to answer that question then you have discharged your duty, i.e. by following CleanSpace's recommended selection and assessment process, and by having a Respiratory risk management process that ensures RPE where used is selected/used/maintained correctly.

Thats correct, hoods and helmets do not require fit testing.