ASTM F2100
ASTM F2100 係一個口罩Standard。
ASTM F2100-11 係 version 2011, which is the current ver。
ASTM Specification
FDA guidance on surgical mask
ASTM Mask Protection Standards – Surgical & Procedure Masks | priMED
ASTM Levels
ASTM Levels and Their Importance to your Mask Selections
Guide to Face Mask Selection and Use
有啲未見過既單位︰
Fluid Resistance, mmHg
• mmHg 係 unit of pressure, 160 mmHg = 21300 Pa = 0.21 atm
Delta Pressure (Breathability), mm H₂0/cm²
• mm H₂0 都係 unit of pressure, 5 mm H₂0 = 49 Pa = 0.0005 atm
• 留意返delta pressure仲要over area
咁ASTM同BFE, PFE有乜關係？
Surgical Face and General-Use Masks Tests | Nelson Labs
要符合ASTM2100就要做以下既測試︰
• 擋菌 Bacterial or Viral Filtration Efficiency (BFE/VFE)
• 通氣 Differential Pressure
• 防火 Flammability test
• 擋粒子 Particle filtration efficiency (PFE)
• 擋血 Synthetic blood fluid penetration resistance for face masks
PFE – Particle Filtration Efficiency
Particle Filtration Efficiency (PFE) Test | Nelson labs
PFE = 可以擋幾多percent粒子，本身冇講粒子係幾大粒。如果係ASTM F2100裡面就講明要試0.1µm PFE。
BFE – Bacterial Filtration Efficiency
VFE – Viral Filtration Efficiency
Bacterial & Viral Filtration Efficiency Tests | Nelson Labs
BFE, VFE = 可以擋幾多percent既病菌、病毒
BFE佢地用Staphylococcus aureus黎test，VFE用bacteriophase phiX174.
睇wiki張圖，一粒Staphylococcus aureus約0.7µm。
Bacteriophase phiX174既大細就搵到一個source話︰
ΦX174 is a small icosahedral, tailless bacteriophage with a maximum diameter of ∼320 Å. (https://www.pnas.org/content/114/52/13708)
Å = 10⁻¹⁰ m, 320 Å = 0.032µm
N95
N95 = filters at least 95% of airborne particles(~0.3 µm). Not resistant to oil.
N if they are Not resistant to oil
R if somewhat Resistant to oil
P if strongly resistant (oil Proof)
CDC – NIOSH – NPPTL Respirator Trusted-Source, Healthcare Related Information, Healthcare FAQs
CDC – NIOSH – Respirator Fact Sheet
Panta rhei 