3.3.2. Particle filters
Particle filters of higher class can be used (with the same mask) in environments where a lower class filter is required.
Filter
class
Type of mask
Multiple of
the limit
value TLV
Observations- Limitations
P1
(low)
Half mask or quarter mask
4
Not to be used against liquid aerosols, radioactive and cancerogenic
materials, microorganisms and active biochemical materials
Full face mask or mouthpiece
4
Infrequent combination
P2
(medium)
Half mask or quarter mask
10
Not to be used against radioactive materials, microorganisms
(bacteria, fungi and moulds) and active biochemical materials
(enzymes, hormones)
Full face mask or mouthpiece
15
P3
(high)
Half mask or quarter mask
30
Not to be used against radioactive materials, microorganisms and
active biochemical materials
Full face mask or
mouthpiece
400
Particle filter should be replaced when an increase of inspiration resistance is noted by the user.
3.4. Filtering Capacity According to EN 143:00/A1:2006
Filter Class
Filtering capacity%
Sodium chloride test Paraffin oil test
P1
80
80
P2
94
94
P3
99,95
99,95
3.4.1. Combined filters
Combined filters offer protection against gases and particles. The conditions and limits of use of these filters are the same
as those for gases and particle filters.
3.4.2.
Multi-type
combined filters
Multi-type combined filters offer protection against various gases and particles. The conditions and limits of use of these
filters are the same as those for gases and particle filters.
3.4.3. AX filters against low boiling organic vapours
A) Organic compounds with a boiling point below 65°C are divided into 4 groups:
Group 1
Organic vapours with a TLV lower or equal to 10 ppm (parts per million)
Group 2
Organic vapours with a TLV higher than a 10 ppm (parts per million)
Group 3
Organic vapours against which protection is given by filters different from the AX type (for example B, E, K)
Group 4
Organic vapours against which the protection given by gas filters is poor or null
B) The filters AX offer protection against the chemical compounds belonging to group 1 and 2 up to the maximum
concentrations as mentioned in the following table. Please take always into account the limitation for use of the various
type of masks (considering as threshold limit the lower value resulting between the two):
Group
Maximum concentration
Maximum time of use
Group 1
100 ppm = (100 ml/m
3
= 0.01 Vol. %)
40 minutes
500 ppm = (500 ml/m
3
= 0.05 Vol. %)
20 minutes
Group 2
1000 ppm = (1000 ml/m
3
= 0.1 Vol. %)
60 minutes
5000 ppm = (5000 ml/m
3
= 0.5 Vol. %)
20 minutes
C) Use new, never used filters only, stored in their original packaging.
D) The use of AX filters for protection against low boiling chemicals mixed with other organic gas/vapour compounds is
forbidden as one or more of these compounds couldn't be filtered.
E) AX filter can be used as A2 filters only in absence of any low boiling compound. A1 and A2 filters must not be used
against organic compounds with a low boiling point.
