9 Common Mistakes When Using a Protective Mask

Even the best protective mask cannot provide reliable protection if it fails to seal, is paired with the wrong filter, or is not properly inspected and maintained. Mistakes made while donning and using a protective mask are often difficult to notice. We examine nine of the most common—from facial hair crossing the sealing surface to filter selection and replacement, cleaning, and proper storage.

Facial hair beneath the face seal, an incorrectly seated mask, or a filter that fits the thread but is not designed for the specific hazard can all compromise the final level of protection. We will therefore examine nine common mistakes involving protective masks, from donning and filter selection to filter replacement, maintenance, and storage.

Read next: Want to know how to identify a genuinely professional protective mask? In CM-6: What Sets a Professional Protective Mask Apart from Standard Civilian Models, we take a closer look at certification, face-seal integrity, breathing resistance, field of view, and other key performance parameters.

1. Improper Donning

Put on the mask, tighten the straps, and you are done? Not quite.

A full-face mask must sit correctly against the face to create an effective seal around its entire perimeter. If the sealing skirt is folded, the mask is sitting crooked, or the straps are incorrectly adjusted, a gap may allow ambient air to enter without passing through the filter.

The solution is not to tighten everything as hard as possible. Overtightening can be uncomfortable and does not, by itself, guarantee a correct fit. The important point is to follow the manufacturer’s instructions and tighten the straps in the specified sequence and manner.

Correctly donning a protective mask should not be something you attempt for the first time when you actually need it. Practice putting it on, adjusting the straps, and performing the required checks in advance.

Even an unused protective mask should not be returned to your kit without inspection. After use, check its condition, perform the prescribed maintenance, and store it correctly. Photo: Rigad

2. Facial Hair or Head Hair in the Seal Area

A full beard may look great. The sealing surface of a full-face mask, however, is unlikely to appreciate it.

The principle is simple. For the mask to seal correctly, its sealing edge must sit directly against the skin. If facial hair, head hair, or another obstruction becomes trapped between the seal and the face, it can create a path for ambient air to enter.

This is not limited to large, full beards. Even short facial hair crossing the sealing line or strands of hair caught beneath the edge of the mask can cause problems. The same attention must be paid to anything else that passes through the area where the mask must seal.

With respiratory protection, even gaps too small to see can affect performance.

3. Skipping the Seal Check

Correctly donning the mask is essential, but the complete protective system must also be checked before use. Even a minor defect or incorrectly assembled component can create a path for unfiltered air to enter.

With the CM-6, for example, particular attention must be paid to the inhalation and exhalation valves and the correct closure of any unused ports. If only one filter is fitted, the second inhalation port must be closed with a plug, and that plug must be properly tightened. The manufacturer also requires a seal test after certain maintenance procedures, such as work on the exhalation valve.

The purpose of this check is to confirm that the complete system remains sealed and that air enters the mask only through the intended route.

A protective mask must maintain a proper seal during movement and while operating other equipment. The final level of protection depends not only on the mask itself, but also on correct donning, its condition, and the selection of a suitable filter. Photo: Rigad

4. Choosing a Filter Simply Because It Fits

It has the correct thread, so it must be suitable. This is one of the most dangerous assumptions you can make.

A standardized connection, such as the Rd 40 × 1/7″ thread specified by EN 148-1, ensures mechanical compatibility between the mask and filter. It says nothing about which hazards that filter protects against.

Particulate filters are designed to capture particles and aerosols. Gas filters contain sorbent media intended for specific groups of gases and vapors. Combination filters perform both functions. Individual filter types are further divided according to their intended use and protection class.

A filter must therefore be selected for the specific hazard, not by its color, price, or the fact that it screws onto the mask without difficulty.

5. Using a Filter for Too Long

A filter does not have an unlimited service life. Unfortunately, there is no simple rule such as replacing it once a year.

In particulate filters, captured particles gradually accumulate during use and may increase breathing resistance. Gas and vapor filters work differently. Their sorbent media has a limited capacity, and actual service life depends on factors including the type and concentration of the contaminant, environmental conditions, the wearer’s breathing rate, and the characteristics of the filter itself.

It is also important to distinguish between the shelf life of an unopened filter and its safe service life after being put into use. The expiration date on the packaging does not mean the filter can be used continuously for any length of time until that date.

You cannot rely on smell either. Some substances may not have a sufficiently noticeable odor, the sense of smell can gradually adapt, and other contaminants may reach dangerous concentrations before the wearer can reliably detect them.

Filters must be replaced according to their type, conditions of use, and the manufacturer’s instructions. Damage, contamination, or any other change in the filter’s condition may also require it to be withdrawn from service.

6. Using an Air-Purifying Mask in an Oxygen-Deficient Atmosphere

This is one mistake that cannot be solved with a better or larger filter.

A filter can remove the contaminants it is designed to capture from the surrounding air. It cannot supply oxygen. If the atmosphere contains too little oxygen, an air-purifying protective mask is not the correct solution.

For example, the manufacturer of the CM-6 specifies a minimum ambient oxygen concentration of 17% by volume when the mask is used with a filter.

This is particularly important in confined spaces, tanks, shafts, and other environments where oxygen levels may fall or the composition of the atmosphere is not reliably known. Under these conditions, suitable breathing apparatus that does not rely on ambient air may be required.

Put simply: a filter cleans the air you breathe. If that air does not contain enough oxygen, there is nothing the filter can do to correct it.

7. Using the Mask Without Inspecting Its Condition

A protective mask is not indestructible. Before use, it is not enough simply to check that you have donned it correctly.

Inspect the facepiece and sealing surfaces, lens, head harness, threads and filter connections, as well as the inhalation and exhalation valves. Even a relatively inconspicuous component can have a critical effect on the performance of the entire mask.

Inspection is also essential after extended storage. For the CM-6, for example, the manufacturer recommends inspecting the inhalation and exhalation valves and performing a seal test at regular intervals during long-term storage.

In other words, the fact that the mask was in working order the last time it was used does not guarantee its current condition.

Physical activity quickly reveals whether the mask fits correctly and whether the complete system provides acceptable breathing comfort and ergonomics. Before use, inspect the mask and filter and verify that all components are assembled correctly. Photo: Rigad

8. Incorrect Cleaning and Maintenance

A protective mask must be kept clean. That does not mean you can use whatever product happens to be in the cleaning cabinet.

The materials used in the facepiece, lens, valves, and other components may react badly to unsuitable chemicals. An aggressive cleaner or solvent can easily do more harm than good. Harsh mechanical cleaning is equally unsuitable—especially on the lens, which should never be scrubbed with an abrasive pad, brush, or anything else that could scratch its surface. 

AVEC Chem, the manufacturer of the CM-6, therefore specifies cleaning and disinfection procedures that should be followed.

Correct reassembly after maintenance is equally important. If any components have been removed, they must be reinstalled correctly, and the mask’s operational condition must be verified before it is used again.

With protective equipment, more aggressive cleaning does not mean better cleaning.

9. Incorrect Storage of Masks and Filters

The final mistake occurs, paradoxically, when the protective mask is no longer in use.

Unsuitable temperatures, humidity, direct sunlight, exposure to chemicals, or prolonged deformation can affect the condition of individual materials. A protective mask must therefore be stored under the conditions specified by the manufacturer and in a way that prevents deformation of the facepiece or other functional components.

Filters require separate attention. With gas and vapor filters in particular, it matters whether they remain sealed in their undamaged original packaging or have already been opened and exposed to the surrounding atmosphere. Storage requirements and continued serviceability must therefore be assessed for the specific product.

The long service life of professional masks illustrates this well. For the CM-6, the manufacturer specifies a combined storage and service life of up to 20 years from the date of manufacture, but only when the prescribed conditions are observed. During long-term storage, it also recommends inspecting the inhalation and exhalation valves and performing a seal test every five years.

Twenty years, therefore, does not mean “leave it in the basement and pull it out in 2046.” Even unused protective equipment requires proper storage conditions and regular inspection.

Even a Professional Mask Cannot Compensate for Every Mistake

A professional protective mask may offer a certified design, durable materials, low breathing resistance, and an effective sealing system. However, the quality of the manufacturer alone does not determine the final level of protection.

It is equally important to select the correct filter, don and inspect the mask properly, use it only under conditions for which the complete system is designed, and follow the required maintenance and storage procedures.

That is why understanding the limitations of protective equipment matters just as much as knowing its specifications. With equipment intended to protect the respiratory system from a hazardous atmosphere, a seemingly minor detail can make the difference between a system that performs as intended and one that merely creates a false sense of security.