01
Purpose
EN 405:2001+A1:2009 specifies performance, testing and marking requirements for valved filtering half masks with integral gas or combined filters. It is not for oxygen-deficient atmospheres or escape devices.
Respiratory ProtectionTECHNICAL PPE LIBRARY
EN 405
Valved Filtering Half Mask Standard for Gases or Gases and Particles
EN 405:2001+A1:2009 specifies performance, testing and marking requirements for valved filtering half masks with integral gas or combined filters. It is not for oxygen-deficient atmospheres or escape devices.
Product type
Valved half mask with integral gas or combined filters
Field focus
Code + product + conditions of use
TECHNICAL PRODUCT IDENTITY
EN 405
EN 405StandardTYPE/CLASSFilter type/classAlways verify the actual product label, manufacturer technical documentation and conformity markings.
02
Typical use
Tasks where risk assessment requires an appropriate integral-filter half mask for specified gases/vapours or gas-plus-particle combinations.
03
What to look for?
Check EN 405 marking, filter type/class, use limits and manufacturer instructions; never select a filter before identifying the contaminant.
CLASSES & SELECTION LOGIC
Technical classes in this standard
A class code is not a selection decision by itself. Interpret it together with task-specific risk assessment and manufacturer data.
GAS
Gas filter
Appropriate filter type is required for the specified gas/vapour group.
COMBINED
Combined filter
Particle filtration can be combined with gas/vapour protection.
NO O2 DEF
No oxygen deficiency
Not for oxygen-deficient atmospheres.
READ THE PRODUCT LABEL
Code & marking decoder
EN 405StandardValved filtering half-mask standard.TYPE/CLASSFilter type/classFilter class matched to contaminant and exposure.
READ THE PRODUCT IN THE FIELD
Where is the standard marking found?
Location varies by manufacturer and design. These are the first places to check; final verification must use the actual product and manufacturer documentation.
1
EN 405 and filter type/class marking on mask body
The marking should be legible, durable and match the product.
2
Packaging/manufacturer instructions
The marking should be legible, durable and match the product.
STANDARD FAMILY
Standards often reviewed together
EN 405:2001+A1:2009Valved half masks with integral gas or combined filters
EN 149Filtering half masks for particles; not gas filters
EN 14387Replaceable gas/combined filters
COMMONLY CONFUSED
They are not the same thing
EN 405 ≠ FFP mask
Gas/vapour filter class differs from particulate FFP class.
WRONG-SELECTION EXAMPLE
A typical field mistake
Using an FFP2 mask for solvent vapour.
Why is this a problem?
A particle filter does not automatically protect against gas/vapour.
Better approach
Identify contaminant and select appropriate EN 405 or compatible gas-filter system.
WHERE IN THE FIELD?
Typical applications
01
Paint/solvent work
02
Chemical maintenance
03
Gas + particle exposure
HSE FIELD CHECK
30-second field check
Use for quick pre-checks. It does not replace certification, competent inspection or task-specific risk assessment.
CHECK FOCUS
Have contaminant and concentration been identified?
CRITICAL MISTAKE
Using an FFP2 mask for solvent vapour.
BETTER APPROACH
Identify contaminant and select appropriate EN 405 or compatible gas-filter system.
1
Have contaminant and concentration been identified?
2
Is filter type appropriate?
3
Are face seal and valves serviceable?
4
Has oxygen-deficiency risk been excluded?
RELATED SERNEM RESOURCES