1. Detailed Meaning of EN 14387
EN 14387 is a key European standard titled “Respiratory protective devices – Gas filter(s) and combined filter(s) – Requirements, testing, marking”
1. Its core purpose is to establish stringent performance requirements, test methods, and marking rules for replaceable gas filters and combined filters (which protect against both gases and particles) used in unassisted respiratory protective devices (like half masks and full-face masks)
1. The standard ensures these filters effectively remove specific hazardous gases, vapours, or a combination of gases and particles from inhaled air, thereby protecting the user’s respiratory system in industrial, medical, and emergency environments . The current and latest version is EN 14387:2021, which replaced the previous draft (FprEN 14387-2020).
2. Applicable Products to EN 14387
This standard applies specifically to two main types of replaceable components for respiratory masks:
- Gas Filters: These are designed to protect against gases and vapours, typically using a bed of activated carbon or other chemisorbent materials . They are classified by the type of gas they filter.
- Combined Filters: These integrate gas filtration with a particulate filter (e.g., meeting EN 143 or EN 149), providing protection against a combination of gases, vapours, and solid/liquid particles (aerosols) simultaneously .
Filters are categorized by Type (defined by the gas family) and Class (defined by capacity). The standard uses a color and letter coding system for easy identification :
- A (Brown): Organic gases and vapours with a boiling point >65°C.
- AX (Brown): Highly volatile organic solvents with a boiling point <65°C.
- B (Grey): Inorganic gases (e.g., chlorine, hydrogen cyanide, hydrogen sulfide).
- E (Yellow): Acid gases (e.g., sulfur dioxide, hydrochloric acid).
- K (Green): Ammonia and organic ammonia derivatives.
- Hg (Red): Mercury vapour and mercury compounds.
- Combination filters are marked with multiple letters (e.g., AB, BK) .
3. Testing Methods of EN 14387
The standard defines several critical tests to validate filter performance:
- Penetration Test (Breakthrough Test): This is the primary test to assess filtration efficiency. The filter is exposed to a standard test gas (e.g., cyclohexane for Type A) at a specified concentration, temperature, humidity, and flow rate. Instruments measure the concentration of the gas downstream of the filter to determine when “breakthrough” occurs, ensuring it stays below strict limits (e.g., 0.001% by volume for Type A) . Tests often include a pre-loading phase to simulate partial saturation from real use .
- Breathing Resistance Test: This measures the pressure drop (resistance) the filter adds to inhalation and exhalation. Limits are set to prevent excessive breathing effort for the user (e.g., a maximum of 2.4 mbar for gas filters and 3.0 mbar for combined filters under a standard flow rate like 95 L/min) .
- Gas Capacity Test: Specialized equipment, known as a Gas Capacity Tester, is used to determine the service life of a filter. It measures the time and total gas volume a filter can adsorb before breakthrough occurs under controlled challenge gas concentrations and flow rates (e.g., 30 L/min) .
- Additional Tests: The standard also includes tests for mechanical strength, climate conditioning, and durability to ensure performance stability in harsh environments .
4. Important Notes on EN 14387
- Regulatory Compliance (CE Marking): Compliance with EN 14387 is essential for obtaining the CE mark under the PPE Regulation (EU) 2016/425. Products must be tested by an EU-notified body .
- Correct Selection is Critical: Filters must be selected based on a thorough hazard assessment of the work environment, including the identification of the specific contaminants present, their concentrations, and the available oxygen level . Using the wrong type of filter offers no protection.
- Limitation of Use: Gas and combined filters are only for use in atmospheres with sufficient oxygen (typically >17% by volume in many jurisdictions). They are not suitable for oxygen-deficient environments .
- Service Life and Replacement: Filters have a finite capacity. The Class (1, 2, or 3) indicates their capacity against increasing gas concentrations, which directly relates to their service life . They must be replaced based on the manufacturer’s instructions, elapsed time, increased breathing resistance, or upon detection of breakthrough (e.g., smell). Expired or damaged filters must not be used .
- Marking Requirements: Each filter must be clearly and permanently marked with its type, class, intended use, and other relevant information (e.g., shelf life, storage conditions) to enable proper user selection .
5. All Other Content Related to EN 14387
- Part of a Standards Ecosystem: EN 14387 is a component within a suite of European respirator standards. It works alongside EN 149 (for filtering facepieces – FFP1/2/3), EN 143 (for particle filters – P1/2/3), and EN 136 (for full-face masks) to provide complete respiratory protection solutions .
- Global Equivalents: The test methods in EN 14387 are very similar to standards used in Australia, New Zealand, Korea, and Brazil, though markings may differ. Similar, but not identical, standards exist in the US (NIOSH), China, and Japan .
- Purpose of Classes: The three capacity classes (1, 2, 3) are designed for different concentration ranges of gases. While all classes capture contaminants with the same initial efficiency, higher classes (2 and 3) have more adsorbent material, providing protection for a longer duration in higher concentration environments. A lower class filter may sometimes be preferred for greater breathing comfort in appropriate conditions.
