Respiratory testing to EN 149

Masks designed to filter out harmful airborne particles and contaminants play a critical role in safeguarding individuals.

Respiratory protective equipment – often referred to as ‘RPE’ – is used in a wide range of industries and situations where harmful dust or gases may be present in the surrounding atmosphere. In Europe, RPE falls within the scope of the Personal Protective Equipment Regulation (EU) 2016/425, so it must be tested, certified and CE-marked before being placed on the market.

To facilitate this, CEN (the European standards body) has developed a number of harmonised European standards, each relevant to a particular type of product. This article describes one such example – EN 149:2001+A1:2009, which describes the performance requirements and associated test procedures for filtering half masks used as respiratory protective devices against particles.

Testing

Compliance signifies that a dust mask meets defined requirements for filtration efficiency, breathing resistance, ergonomic design and compatibility with various facial shapes and sizes. There are also requirements for the packaging.

The standard defines performance requirements for three classes of particle-filtering half-masks. A mask conforming to the standard must have its class written on it, along with the name of the standard and its year of publication, as well as any applicable codes to denote limitations of use – for example, ‘FFP1 NR D’.

Within EN 149:2001+A1:2009, particle filtering half masks are classified according to their filtering efficiency and their maximum total inward leakage. There are three classes as shown in table 1, and the applicable class should be clearly displayed on the mask itself.

Table 1: Classifications of half masks
Class	Filter penetration limit	Inward leakage
FFP1	Filters at least 80 per cent of airborne particles	< 22 per cent
FFP2	Filters at least 94 per cent of airborne particles	< 8 per cent
FFP3	Filters at least 99 per cent of airborne particles	< 2 per cent

In addition, particle filtering half masks are classified as ‘single shift use only’ or as ‘re-usable’ (more than one shift). A mask intended for single shift use, and therefore non-reusable, is typically marked with the letters ‘NR’. A reusable, multi-shift mask, is marked with the letter ‘R’.

If claiming resistance to clogging, the markings should include the letter ‘D’. Testing to achieve this claim is optional for non-reusable half masks. However, it is a mandatory requirement for reusables.

EN 149:2001+A1:2009 is the current harmonised European standard for filtering half masks used as respiratory protective devices against particles. It specifies the technical requirements, testing methods and marking for filtering half masks to protect against particles.

Tables 2 to 8 contain a summary of the key testing and performance requirements.

Table 2: Breathing resistance
Brief description		Requirement
The breathing resistance test apparatus measures the drop in pressure across the mask during inhalation and exhalation.		The mask shall provide adequate inhalation and exhalation resistance so that the user can breathe safely.

Table 3: CO2 content of inhalation air
Brief description	Requirement
This test involves the mask in a simulated wear position with CO2 incorporated. A measurement is taken as the mask inhalations to assess how much CO2 is retained in the mask and inhaled, compared to how much is leaving the mask through the filter material or exhalation valves	The CO2 content of the inhalation air shall not exceed 1 per cent by volume.

Table 4: Filter penetration
Brief description	Requirement
The penetration tests consist of loading the filtering material with paraffin oil mist and sodium chloride mist solution. Permissible penetration of the filter material depends on the rating of the mask.	Maximum penetration of test aerosol: FFP1 – 20 per cent FFP2 – 6 per cent FFP3 – 1 per cent
If claimed to provide resistance to clogging, the sample is loaded with dolomite dust. Further testing is then required by checking breathing resistance and penetration with both test methods after the mask has been loaded with dust.	The mask must still pass the requirements for breathing resistance and penetration based on the grade of the mask.

Table 5: Flammability
Brief description	Requirement
Samples donned onto a metallic head form, the head form wearing the mask is then passed through a small flame in the ‘as worn’ position. Testing is repeated to ensure all materials of the mask are tested.	The mask must not continue to burn for longer than five seconds if ignited.

Table 6: Leakage
Brief description	Requirement
The total inward leakage test involves the use of subjects and apparatus to measure the masks’ ability to provide a proper seal against the face. This is judged by the participant correctly wearing the face mask and performing walking tasks. Continuous readings from within the mask are taken to check how much of the solution is detected.	The mask’s total inward leakage as well as the arithmetic means of the test subjects shall not be greater than the requirement based on the grade of the mask. This can range from 25 per cent to 2 per cent, based on mask grade.

Table 7: Materials
Brief description		Requirement
Simulated wear treatment: This consists of having a mask on a dummy head, a breathing machine and a humidifier supplying air at 37°C. The mask is conditioned in this way for 20 minutes, removed and then replaced back onto the dummy head. This is repeated ten times. This simulates a mask being worn for longer periods.		No deformation of the sample after the conditioning periods. Assessment that the mask still correctly functions and passes penetration and breathing resistance requirements as per the grading of the mask.
Temperature conditioning: This is to test if the products can withstand different temperatures and humidities without deformation. The conditioning cycle is: 24 h at a dry atmosphere at 70°C 24 h at -30°C		No deformation of the sample after the conditioning periods.
On reusable masks, a cleaning and disinfecting cycle is used to see if this process changes the product materials in any way. This will be assessed during the total inward leakage and penetration tests, as well as a visual check.		No deformation or damage to the sample after the cleaning and disinfecting process. Results from the total inward leakage and penetration tests shall still meet the relevant requirements as per the mask rating.
Innocuousness testing is also conducted to ensure that the materials used are safe without adverse effects to health.		The mask shall not contain chemicals that may harm or irritate the wearer.

Table 8: Practical performance
Brief description	Requirement
This test is used to check the product for possible issues that would not be found during other testing. This can include mask comfort, fitting of the headband and field of vision. The test consists of two exercises: Walking test: Walking on a level surface for ten minutes at a rate of 6 km/h with the mask donned correctly. Work simulation test: Three exercises to simulate the mask being used for a full work session. Walking on a level with headroom of 1.3 m. Crawling on a level with headroom of 0.70 m. Filling a small basket with chippings and emptying them into a hopper for ten minutes.	This test is subjective, and pass/fail is based on the comments of the individual. Each part is assessed on its own, so only one part could fail or all parts. Field of view: Assessment based on how well the subject can see. Mask comfort: Assessment based on how comfortable the mask is to wear during use. Headbands: Assessment based on whether the headbands hold the mask in position for the duration of the exercises. Whether the headbands are easy to use and comfortable.

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