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Motorized Air Purifying Respirators, Respiratory Protection with Filter

Powered air purifying respirators is the highest level of filtration respiratory protection. Unlike classic gas masks, they are positive pressure devices. This, It means that the respiratory effort is lower because it is done by the motor, not the user, by constantly sending a stream of filtered air to the face piece (mask, hood, welding curtain). Therefore, devices difficult, tiring, long-term work It is better to use it for interventions in high temperature environments.

Classic respirators with motorized air purification

Powered air-purifying respirators are more elaborate filtering respiratory protection devices. They consist of a face piece (mask, hood, welding shield), one or more respiratory protection filters (particulate, anti-gas or combined), a light motor and a ring hose. A motorized fan delivers filtered air directly to the facepiece through the corrugated hose, resulting in a lower respiratory effort. The main advantage of a positive pressure filtration respiratory protection system is the reduction in respiratory effort.

Recently, many manufacturers of motorized ventilation equipment have offered ALL-IN-ONE systems in which the motor, battery and filter are attached directly to the head, thus avoiding any devices worn on the belt (cables, hoses, motors or batteries) for maximum freedom of movement and without the risk of snagging. The two manufacturers offer this unique and very useful type of equipment, which is compatible with other personal protective equipment (welding helmets, hazmat suits, fall arrest harnesses, etc.) such as CleanSpace masks or Gentex ventilated helmets.

In standard or ALL-IN-ONE versions, the powered air purifiers are recommended for strenuous, strenuous and long-term work or interventions in hot environments. Moreover, the excess pressure generated in these filtering devices with assisted ventilation guarantees a much higher nominal protection factor than in a classic gas mask.

ATEX supported air purification equipment

ATEX supported air purifiers are designed for explosion-risk environments where flammable gases, vapors or dust are potentially present. They are popular in refineries, gas pipelines, storage tanks (solvents, alcohols, dyes), printing plants, chemical and pharmaceutical industries or mining.

a In this case, together with the AX-P2 filter, the CleanSpace Ex ATEX PAPR mask is currently the only ATEX powered respirator capable of filtering VOCs! Provides effective protection against fine solid or liquid particles and volatile organic compounds (VOCs) from solvents with boiling points of 65°C or lower, such as acetone, methanol or methyl bromide.

Hoods and powered air-purifying respirators

PAPR hoods

Hoods are manufactured from a flexible material that is resistant to certain corrosive gases. It covers the entire head and has a wide field of vision. Motorized air purifying hoods feature an air distribution device for greater comfort.

Motorized air purifying masks

Powered air-purifying respirators are the face mask of choice when pollutant concentrations exceed 40 times the OEL (8-hour occupational exposure limit). The air sent from the powered air-purifying respirator reaches directly close to the respiratory tract and prevents the eye mucous membranes from drying out.

The filtration performance of powered air-purifying respirators depends on the tightness of the entire device (facepiece, motor, and filter). A letter (heading family) associated with a number (the tightness level of the powered ventilation device) indicates these.

Tightness is measured as the percentage of “contaminant gas” leaking into the facepiece. “Polluting particles” are designated by the letters PSL (for solid and liquid particles) without specifying an efficiency class:

TH (Turbo Hood) for hood type face pieces

  • TH1 stops 90% of aerosols (i.e. 10% penetration)
  • Stops 98% of TH2 aerosols (i.e. 2% penetration)
  • Stops 99.8% (i.e. 0.2% penetration) of TH3 aerosols

TM (Turbo Mask) for face parts such as a mask or half mask

  • TM1 stops 95% of aerosols (i.e. 5% penetration)
  • TM2 stops 99.5% of aerosols (i.e. 0.5% penetration)
  • TM3 stops 99.95% of aerosols (i.e. 0.05% penetration)

⇒ For motorized air cleaners respiratory protection filter find

Usage limits of powered air purifying respirators

Never use filtering respiratory protection in the following situations:

  • Ambient oxygen level < 19%
  • In confined spaces or in all areas with little or no ventilation: tanks, tunnels, boat holds, etc.
  • If the concentration of the pollutant is unknown or immediately lethal to humans (IDLH)
  • When the concentration of the pollutant is above the maximum allowable concentration or beyond the capacity of the filter

In such cases, self-contained breathing apparatus will need to be used.

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Gas Mask – How to Choose Your Respiratory Protection

Gas mask, half mask and EN140 standard for full face mask It is a personal protective equipment (PPE class 3) subject to the EN136 standard for The most popular models have 40mm universal filters, mainly due to the wide range of filters available They are single cartridge DIN Rd40 versions (standard EN148-1). Double filter models, They are more compact, have a wider field of view and better load balance than those designed for routine applications or meticulous work.

Half mask

It only covers the lower part of the face (nose and mouth). It consists of a flexible seal and clamps to ensure a tight seal of the airways once set. However, there are two main restrictions on its use:

  • The substances to be filtered are chlorine, ammonia and its derivatives or nitric acid, sulfuric acid, hydrochloric acid etc. It should not be irritating to the eyes.
  • Respiratory protection filters must not exceed 300 grams in weight, which significantly limits combined gas and particle configurations, such as the ABEK2-P3 cartridges most commonly used in the industry, weighing in excess of 300 grams.

Full face mask

It covers the entire face, nose, mouth and eyes. It is particularly suitable for use in environments that are highly toxic, corrosive or potentially hazardous to the mucous membranes of the eyes.

It has five attachment points for fixing to the face and can support filter cartridges weighing more than 300 grams (and are therefore more effective because they have more filtering elements), such as REACTOR filters (radioactive iodine) A2B2E2K1-P3 Reactor or CO/NO filters ABEK2HgNOCO20-P3 .

Single cartridge RD DIN 40 gas mask or double cartridge gas mask?

There are two main categories: single-cartridge masks equipped with RD DIN 40 filters (40 mm universal standard thread) and double-cartridge masks, which are more compact, have a wide field of view and have better load balance.

rd40 masks It has a wide range of filters (EN148-1 compliant). Due to their universality – all major brands of respiratory protection equipment offer RD DIN 40 filters – a wide range of filter cartridges are available.

Double cartridge masks It has two side filters. These dual-filter devices have several attractive advantages: an excellent load balance (loads are better shared) and a wider field of view because the filters are positioned laterally on the side of the face.

Respiratory protection mask use limits

Filtered respiratory protection devices should not be used in the following situations:

  • When the oxygen level in the air is insufficient (below 19%).
  • In confined spaces (see CATEC ) or in all areas with little or no ventilation: tanks, vats, silos, tunnels, ship holds, etc.
  • If the contaminant concentration is unknown or immediately lethal to humans (IDLH).
  • When the pollutant concentration is above the maximum allowable concentration or beyond the filter capacity.

Filter cartridges for gas masks

There are three categories: Particle filters (dust, aerosols, bacteria, viruses), anti-gas filters (organic, inorganic gases and vapors, acids, etc.) and combined filters (gas and particles).

Particle filters

Different particle filter classes:

  • Class P1 filters: low efficiency, this stops at least 80% of the aerosol (i.e. less than 20% penetration)
  • Class P2 filters: medium efficiency, this stops at least 94% of the aerosol (i.e. a penetration of less than 6%)
  • P3 class filters (high efficiency): This stops at least 99.95% of the aerosol (i.e. less than 0.05% penetration)

Anti-gas filters

There are different types of anti-gas filters depending on the nature of the gas or vapor. A marking consisting of a letter associated with a color indicates each filter type specific to each gas or gas family according to European standard EN14687. Similarly, for each gas or family of gases, there are three respiratory protection efficiency classes defined by EN143 and EN143/A1 standards:

Depending on the type of filtering device, the maximum permissible concentrations of toxic substances (gases or vapors) will be different, i.e. 50 x OEL for half masks and 2000 x OEL for full face masks. According to these parameters, the three efficiency classes of gas filters are:

  • Class 1: Wafer filter (example A1 or ABEK1) – small capacity and low efficiency, gas content by volume below 0.1%.
  • Class 2: Cartridge filter (example: A2B2 or ABEK2) – medium capacity, gas content by volume less than 0.5%.
  • Class 3: For gas contents of less than 1% by volume.

Combined anti-gas and particle filters

As the name suggests, combined filters It stops both gases and particles. The air first passes through the particle filter element (which also acts as a pre-filter) and then through the gas absorbing element (activated carbon). Their coding retains the same principle, a group of letters (for gases), a number (for efficiency class) and class level for particles: example ABEK2-P3.

⇒ Find the right respiratory protection filter for your application

Maintenance and annual control of masks

Respiratory protection masks are class 3 personal protective equipment. Therefore, like all class 3 PPE, they are subject to annual periodic inspection. This periodic check includes:

  • Clean thoroughly with water to remove any splashes (mud, saliva, etc.).
  • For a more thorough clean, machine wash with a cleaning and disinfecting product
  • High temperature drying
  • Verification of pressure and leakage parameters on the control bench
  • The mask should be individually bagged to ensure it is clean and healthy.

GTC Industrial - Dräger's authorized maintenance center - carries out all annual periodic checks of Dräger respirators in our maintenance laboratory. Feel free to contact us for this class 3 PPE maintenance.