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¡¡ Activated CarbonFiber Mask |
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Mask International Specification |
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For function index of mask, there are Bacterial Filtration Efficiency (BFE)
and Particle Filtration¡¡Efficiency (PFE), and these are specified by international
specifications.
¡¡¡¡¡¡¡¡¡¦Europe: EN specification (EN149)
¡¡¡¡¡¡¡¡¡¦National Institute for Occupational Safety and Health: NIOSH specification
¡¡¡¡¡¡¡¡¡¦Japan National Assay Specification |
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EN Specification CE EN149 |
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EN specification is European standards which were build due to the integration
of the EU.
EN149FFP is for dust respirators which is satisfied of EN specification.
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NIOSH Specification |
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National Institute for Occupational Safety and Health (NIOSH) in Department
of Health and Human Services established this specification for dust respirators.
With regard to N95, N means not resistant to oil. In addition, 95 indicates
that a mask can catch test particle more than 95%. According to tuberculosis
infection prevention guideline in U.S. Centers for Disease Control and
Prevention, the specification is established for prevention of aerial infection.
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Japan National Assay Specification |
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Health, Labour and Welfare Ministry in Japan established this specification
for dust respirators.
In case of work in dusty environment, it must use masks satisfied with
national assay, that doesn't need for virus prevention and disaster sites. |
Comparison of International Specification for dust respirators |
Specification |
Europe EN Specification |
U.S. NIOSH Specification |
Japan National Assay Specification |
Particle |
NaCl |
NaCl |
NaCl |
Size |
0.6¦Ìm¢¨ |
0.075+0.02¦Ìm |
0.06¡Á0.10¦Ìm |
Type |
Disposable |
Disposable |
Disposable |
PFE |
FFP1¡§¡æ80%
FFP2¡§¡æ94%
FFP3¡§¡æ99% |
N95¡§¡æ95¡ó
N99¡§¡æ99¡ó
¡¡N100¡§¡æ99.97¡ó |
DS1¡§¡æ80¡ó
DS2¡§¡æ95¡ó
DS3¡§¡æ99.9¡ó |
Note |
FFP¡§Filtering Face Piece
FFP2¡§Middle Level
FFP3¡§High Level |
N¡§Not resistant to oil |
D¡§Disposable
S¡§Solid |
¢¨Test particle diameter for EN specification is mass median aerodynamic
diameter.
The size is same with 0.06 ¦Ìm ¡¡in Count Median Diameter, which is indicated
by U.S. NIOSH and Japan National Assay Specification.
¢¨U.S. specification N95 is same as EN specification FFP2 and Japan National
Assay specification DS2.
¢¨Since there is no standard international specification for masks, testing
method varies by each specifications and we cannot simply compare the numerical
value. |
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Medical mask specification |
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There is no standard specification for medical masks function in Japan.
However, the prevention function against fluid such as moist body substance
is required in medical front.
As medical mask function, Bacterial Filtration Efficiency (BFE) and Pressure
Drop (ùP) are main required specification. In addition to these specification,
Particle Filtration Efficiency (PFE) and Fluid Resistant (FR) are required
depending on mask grade.
The following indicates U.S. medical mask specification ASTM (Americn Society
for Testing and Materials) F2100.
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Medical Mask Specification (ASTM F2100-4) |
Characteristics |
Low level |
Middle Level |
High Level |
BFE |
¡æ95¡ó |
¡æ98¡ó |
¡æ98¡ó |
PFE |
¡½ |
¡æ98¡ó |
¡æ98¡ó |
¢¤P |
¡ã4.0mmH2O/cm2 |
¡ã5.0mmH2O/cm2 |
¡ã5.0mmH2O/cm2 |
FR |
80mmHg |
120mmHg |
160mmHg |
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Function index of Mask |
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Bacterial Filtration Efficiency ¡ÚBFE¡Û
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It indicates filtration efficiency when particles, including bacterium,
which average size is 3¦Ìm are filtered.
Staphylococcus (approximately 3¦Ìm) is used to test the function of a mask.
The function of a mask is better when the number is high. In case of medical
masks, it should be more than 95 %.
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Particle Filtration Efficiency ¡ÚPFE¡Û |
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It indicates filtration efficacy when fine particles, which average count
median diameter isapproximately 0.1¦Ìm are filtered.
Fine particles (0.1¦Ìm) is used to test the function of a mask. The function
of a mask is better when the number is high.
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Air Exchange Pressure ¡ÊmmH2O/cm2 ¡Ë¡Ú¢¤P¡Û |
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It indicates the easiness of breathing.
Certain amount of air is passed through masks, and the difference of pressure
between both sides are measured.
When the difference is small, it indicates the resistance is small, so
that it is easy to breath.
The important point for high function mask is the balance between high
level of filtration efficacy and low level of pressure drop.
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Fluid Resistant ¡ÊmmHg¡Ë ¡ÚFR¡Û |
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It indicates the resistant toward fluid when fluid are spread out.
Pressure which is same as blood pressure (80,120,160mmHg) are pass through
masks, penetration to the opposite side of mask is checked by eyesight. |
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