对胡须的常规要求

Powered Air Purifying Respirator (PAPR) for beards

这里的问题是关于佩戴口罩或呼吸器时的呼吸防护问题。

这里，“呼吸器”可以分为 空气净化呼吸器（APR） 和 动力空气净化呼吸器（PAPR）。

Within PAPRs, we have Tight-Fitting PAPRs and Loose-Fitting PAPRs.

这里，“紧密贴合”是指呼吸器和皮肤之间的面部紧密密封，设计目的是为了无泄漏； “宽松贴合”是指呼吸器和皮肤之间有意设计的非严密密封，以放宽贴合要求，允许少量泄漏。

Typical tight-fitting respirators involve an elastomeric facial cushion, and typical loose-fitting respirators involve a helmet, a visor, or a hood. Where the blower and hose sit changes the picture again — we compare the four main types of PAPR separately.

Except for Loose-fitting PAPRs, clean-shaven is the common requirement for wearing a tight-fitting respirator, especially a paper mask or an APR.

宽松贴合型 PAPR 适合有胡须的人配戴，是这样吗？

Loose-fitting PAPRs are designed not to rely on a tight seal to ensure protection, instead, they rely on positive pressure generated by the PAPR in the breathing zone to block outside contaminants from getting through the gaps in the loose-fitting partial seal while the PAPR sucks air via a filter.

但为了能按这个方法正确的工作，鼓风机需要产生可供佩戴者呼吸的所有气量，如果这种 PAPR 能够实现这一点，那么是的，它确实适用于有胡须的或者有面部毛发的佩戴者。

然而，这里可能存在误解，认为宽松贴合型 PAPR 完全适用于有胡须的佩戴者，而不考虑其局限性。事实上，其适用程度是很受条件限制的，并且在应用中可能会受多个因素的制约，例如：

• 面部毛发有多长以及其分布的位置？
• 所使用的宽松贴合型PAPR 的鼓风能力有多强？
• 如何控制气流？内置电池电量低时流量会变少吗？
• 体力劳动对您呼吸的负荷有多大？
• 污染物的浓度有多大？
• 污染物的最大暴露限值是多少？

Most of these factors are related to the single most essential characteristic of PAPRs: Positive Pressure in the mask/breathing zone. As long as positive pressure is maintained all the time, there will be no leak issue from facial hair, as the air tends to be pushed out of the mask instead of being sucked in.

理论上，只要PAPR中鼓风机产生的气流不小于吸入流量，就可以维持正压。但实际上，对于宽松的头盔、护脸罩或头罩，泄漏路径会多变，因此并非所有来自鼓风机的气流都能到达呼吸区域。有些气流可能会在到达呼吸区之前就泄漏出去了。

Therefore, the PAPR needs to be designed in such a way that it generates a flow more than what the wearer can breathe plus the flow leaked over the loose-fitting interface.

PAPR能产生多少气流取决于PAPR的鼓风能力；然而，吸入的空气流量取决于您工作时需要多用力呼吸。

可现实情况是，PAPR 可以产生的最大流量是有限的，并且当使用一定时间电池电量变低时，其流量也会低于初始水平。

此外，大多数宽松贴合型PAPR提供的是恒定的流量。这样流量越高，要求的电池容量也会相应增加，这会使电池变得更大、更重，因而降低可穿戴性并增加成本。

On the other hand, if your job is highly physical and causes heavy breathing, your inhaled air could outrun what the blower can deliver.

The other important factor to consider is the protection factor requirement of the PAPR for doing certain work. The concentration of the contaminants and the maximum exposure limit will determine the minimum protection factor of the PAPR. Typically, loose-fitting PAPRs have a lower protection factor than tight-fitting PAPRs. When the contaminant exposure limit demands a PAPR with a high protection factor, loose-fitting PAPRs may not be suitable, regardless of whether you have a beard or not. Welding fume is a recent example: Australia’s welding fume exposure standard is now 1 mg/m³, down from 5 mg/m³.

因此，为了确保所选宽松贴合型PAPR 适合某种作业，特别是对有胡须的人，需要根据具体情况进行仔细评估。  

紧密贴合型 PAPR 可以用于有胡须的人吗？

当鼓风机的流量、所使用的过滤器和系统泄漏量相当时，紧密贴合型 PAPR通常比宽松贴合型PAPR具有更高的防护系数。

This is because during a negative pressure condition, when the inhaled air outruns the air delivered from the blower, a tight-fitting mask will let in much less outside air compared with a partially sealed loose-fitting covering.

Typically, a tight-fitting mask is made of soft silicone rubber that contacts the front of the face, and it is elastic enough to adapt to the contour of the face to achieve a good seal. In contrast, a loose-fitting covering typically uses elasticized fabric at the contact interface, and it may cover a much larger area, such as the head, the face, and the neck, than only the front of the face.

Now, if the beard is short enough such that the silicone cushion from the tight-fitting PAPR can still achieve a better seal than loose-fitting PAPRs, there is no reason why the tight-fitting PAPR can’t work as effectively, if not better than a loose-fitting PAPR, given the loose-fitting covering has more leaks.

As an example, AYO WX HFM Standard Half-Face Mask PAPR System, which has a well-designed silicone facial cushion, was tested on a light-beard person achieving an average PortaCount fit factor over 2000 when powered on, similar to a clean-shave person under the same test conditions and far better than a non-powered respirator of typically only between 100 to 500. The key reasons AYO WX PAPR can achieve this are due to its powerful peak flow of over 200 L/min, which is similar to most loose-fitting PAPRs, and also due to its positive pressure ensured by the responsive flow control that can quickly accelerate the blower output anytime when the inhalation increases.

So to answer the question, yes, a tight-fitting PAPR can be used with a light-beard person similarly to a loose-fitting PAPR, provided the facial cushion is well designed, the beard is reasonably short, the flow generation is powerful enough, and most importantly, the ability to ensure positive pressure inside the mask.

Having said that, the EU highest class TH3 for loose-fitting is not ideal for work conditions that require a minimum protection factor of 1000 with heavy breathing, as once the breathing outruns the blower, negative pressure will be created in the breathing zone, causing leaks to contaminants. In this situation, a tight-fitting PAPR is more appropriate, and loose-fitting PAPRs are normally limited to light to moderate workloads for a protection factor of up to 500.

总而言之，下面是我们对有胡须人士的建议

• 佩戴负压呼吸器时，必须将胡须刮干净。
• You should be clean-shaven whenever you can, even if you wear a PAPR.
• If you insist on keeping your beard, you must use a PAPR and make sure:
  • Trim your beard to a minimum.
  • Use for work with light to moderate exertion.
  • 使用 PAPR 前请将电池充满电。
  • 避免使用堵塞的过滤器——要经常更换过滤芯。
  • 尽量选用可以产生较大气流的 PAPR。
  • 尽量选用具有较小泄漏和设计优良的弹性脸衬的 PAPR。
  • Try to use a PAPR with powerful and intelligent breath-responsive flow control like an Aimwell® AYO™ WX.

If the beard stays, the direct route is a facepiece that never seals against skin: the AYO WX FFM-LF loose-fitting full-face PAPR, which needs no clean shave and no fit test.

Choosing the respirator is only half of it. The employer still carries the training, fit testing and record-keeping duties: see PAPR training requirements for Australian employers.

Related reading

• Can Facepieces be Loose-fitting?
• Is Fit Testing for Respirators a Flawed Practice?
• How Does Aimwell™ AYO™ WX FFM-LF P-Boost Full-Face Mask PAPR System Compare with Other Full-Face PAPR Brands?

There are many kinds of PAPRs on the market, and if we categorize them based on their structural styles, we could have the following categories:

• On-facepiece
• In-helmet
• Hose & Belt – Facepiece
• Hose & Belt – Helmet/Hood
• Around-neck

Here is a quick go-through of them.

On-facepiece

• Compact
• Heavy on the face
• Affect downward vision and work
• Difficult to use in confined spaces
• Difficult to implement on half facepiece

In-helmet

• Include head protection by design
• Heavy on the top – difficult for downward work
• Difficult to use in confined spaces
• Loose-fitting only – lower protection
• Not feasible to half-facepiece
• No choice but to wear the helmet even if you don’t want to

Hose & Belt + Facepiece

• Hose-on-face affects work and vision
• Hose affects mobility
• Difficult to use in confined spaces
• Troublesome to don and doff

Hose & Belt + Helmet/Hood

• Include head/eye protection
• Hose affects mobility
• Difficult to use in confined spaces
• Troublesome to don and doff
• Not feasible to half-facepiece
• Loose-fitting only
• No choice but to wear the helmet or hood even if you don’t want to

 Around-neck AYO WX PAPR Series

• Low profile on the face
• Good mobility
• Easy to don and doff
• Can work with half-facepiece and full-facepiece
• Flexible to add other PPE

It can be appreciated that the Around-neck AYO WX PAPR series is more practical and flexible than all other styles:

• With low-profile facepieces that matter most when doing challenging hard work including downward work and in confined spaces.
• No top-heavy helmet-mount PAPR that affects downward work.
• No hose & Belt that affect mobility and working in confined spaces.
• As it is around the neck, it is compatible with most common helmets, earmuffs, etc.
• It allows flexibility of half-facepiece, full-facepiece, with or without a helmet, use of common and non-integrated helmets, including common welding helmets, etc.

Equipped with a world-leading breath-responsive flow control technology, the AYO WX PAPR series is capable of producing over 200 L/min peak flow when needed, yet it can work efficiently for up to 16 hours with a much smaller and lighter battery than in those of constant flow PAPRs.

By using advanced and smart technologies, AYO WX can be fitted around the neck, which demonstrates the best location to fit a PAPR for doing a wide range of industrial works.

AYO WX Around-neck PAPR Series is proudly invented, designed, and optimized in Australia by Aimwell.                                                                                                                  

Related reading

• PAPR Types: Four Ways to Wear a Powered Respirator
• How Does Aimwell™ AYO™ WX HFM P-Boost Standard Half Face Mask PAPR System Compare with Other Half Face Mask PAPR Brands?
• Why Paper Masks/Non-Powered Respirators Are Inadequate for High-Exertion Work?

When it comes to half-face respiratory protection from dust, typically there are 3 options:

1. Disposable paper mask, commonly N95 paper mask or filtering facepiece respirator (FFR).
2. Elastomeric reusable non-powered air-purifying respirator (NAPR).
3. Powered air-purifying respirator (PAPR).

Option 1 is the most common type of respirator, where the ‘Cup’ shaped mask is made of non-woven filter media and thus functions both as a barrier and as an air filter.

It is simple, light, low-profile, and can be mass-produced efficiently; however, it has the following key drawbacks:

• The seal is prone to leak, as the facial contact is made from non-woven fiber that is not elastic with a low fit factor and cannot maintain a reliable seal with facial movement.
• Typically, P2 grade is most practical from a flow resistance point of view due to the limited effective usable area of the mask, and P3 grade media will likely make it too restrictive to breathe comfortably.
• The Assigned Protection Factor (APF) is only 10 for P2 FFR. For hazardous dust such as welding fumes, it is considered inadequate.
• It is a disposable type and is not designed for reuse. Outside dust tends to accumulate around the mask seal due to negative pressure inside the mask, making it dirty to reuse the next day. Your breath will also contaminate the filter media with moisture and smell, increasing flow resistance to breathe against, and allowing bacteria to grow. Depending on how dusty and physical exertion is, it may need to be replaced in a few hours or daily.
• You must be clean-shaven.

Option 2 improves some drawbacks of Option 1, where:

• The elastomeric cushion improves the fit factor and seal during use.
• The filter and the elastomeric mask are reusable, making it environmentally friendly and potentially saving costs for frequent use in dusty environments.

However, Option 2 still has the following drawbacks:

• Although the flow resistance of the filter of a NAPR can be made lower by making the filter cartridge bigger, being a negative pressure respirator, the APF is still at 10 regardless of whether a P3 grade filter is used.
• Being a negative pressure respirator, your lungs are still burdened by the flow resistance of the filter, making it not very suitable for high exertion work, as the flow resistance is proportional to the flow rate which is determined by the level of exertion of the work involved.
• You must be clean-shaven to ensure the expected protection, and you are also recommended to do annual fit testing to make sure the fit factor is still adequate.

Option 3 improves most of the drawbacks of Option 2, where:

• There is no flow resistance when the pressure inside the mask is positive, which is the case in normal and non-high exertion work where the flow rate from breathing is within the flow capacity of the PAPR.
• Higher APF can be achieved up to 1000.
• You may be able to keep a short and well-trimmed beard, provided you do fit testing at least once to make sure a fit factor of over 1000.

So based on the above comparison, PAPRs are the best option as far as protection is concerned.

However, not all PAPRs are equal:

• • They vary with APF levels, some are not significantly higher than a NAPR, such as a loose-fitting PAPR.
  • Other factors such as wearability, mobility, flow capability, and cost will affect whether a particular PAPR is suitable for a given work.

Here is a comparison of popular types of PAPRs on the market for dust protection:

From the table above, Aimwell AYO WX HFM Half-Face Mask PAPR System is a clear winner among common half-face mask PAPRs on the market in terms of overall performance for dust protection.

You may wonder why Aimwell AYO WX HFM PAPR System comes only at a fraction of the cost of most PAPRs while achieving the best overall performance on the market.

You can better appreciate it with our mission as a company: to make you breathe safer and better. We mean it by striving to innovate the technology, the design, and the manufacturing process to make the product work better and cost less.

In the case of Aimwell AYO WX HFM PAPR, firstly the technology used is unique and among the most advanced in the world, then we went a step further to make the overall product cost less by optimizing the design for a low-cost manufacturing process, and we went even further to make the running cost very low by providing an unconventional pleated pre-filter not seen in other respirators.

As a result, the running cost of Aimwell AYO WX HFM PAPR is so low, that within 12 months, its total cost after purchase will be less than that for a common NAPR.

In summary, Aimwell AYO WX HFM Half-Face mask PAPR System has the following properties:

• Best-in-class protection and lowest-in-class cost.
• Great wearability and mobility – can be worn just like a common NAPR.
• Comfortable to breathe – once you have used Aimwell AYO WX HFM PAPR, you will not want to go back to NAPR.
• Easy to clean and maintain – flush wash compatible.
• Less demanding on clean-shaven with a Loose-Fitting Face Seal as an Add-on option.
• Cheaper than using a NAPR.

So if you are looking for the best half-face respirator for dust protection, look no further than Aimwell AYO WX HFM PAPR.

Aimwell AYO WX HFM PAPR is ideal for protecting the following: Asbestos, silica dust, metalliferous dust, powder coating dust, coal dust, and sawdust.

Upgrade from NAPR to Aimwell AYO WX HFM Half-Face Mask PAPR System now for better protection, better comfort, and cost savings.

Related reading

• 如何有效防护二氧化硅粉尘
• How Does Aimwell™ AYO™ WX HFM P-Boost Standard Half Face Mask PAPR System Compare with Other Half Face Mask PAPR Brands?
• Case Study – Running Cost Comparison Between a NAPR and an AYO WX HFM P-Boost