Thread by @ScientistAndre

📢🚨 Big update for healthcare & community mask users! 😷

The new EN 14683 standard (v2025) on medical masks just dropped with key updates.
Let's dive into the changes 🧵👇
⚠️ TL;DR: Medical (surgical) masks are NOT PPE! They are designed to protect others, not wearers.

0/ 🔍 What's new in EN 14683:2025?
- Clearer design specs: Ensures masks meet consistent quality standards.
- Defined use cases: Specifies when & where medical masks are appropriate.
- Transparent masks option included: Supports accessibility for lip-reading & communication.
- User info annex: Practical guidance for proper mask use.
- Rationales annex: Explains the science behind testing methods (I personally like this one)

1/ Intended Use: Source control, Not PPE 😷
EN 14683:2025 emphasizes that medical face masks are primarily designed to protect patients by reducing the spread of larger droplets from the wearer’s mouth/nose, especially in surgical and medical settings. They’re not classified as PPE (e.g., respirators under Regulation (EU) 2016/425).
These masks focus on outward protection (source control) rather than inward protection against airborne hazards. It specifies that for workplace respiratory risks, CE-marked respirators are required. 👏
The standard doesn’t specify inward leakage performance, highlighting that masks aren’t designed to fully protect the wearer from small aerosols.

2/ New: Transparent Medical Face Mask (TMFM)
TMFMs aid communication (lip reading, cognitive impairments):
- Breathability tested on porous areas.
- Addresses condensation, acoustics, visibility.

3/ Design & Leakage
Clause 5.2 clarifies that masks don’t seal tightly. Bypass leakage (air escaping around edges) isn’t quantified in the standard, affecting small particle filtration.
The filtration efficiency in table 1 only accounts for the material filtration capacity, not the leaks

4/ Bacterial Filtration Efficiency (BFE) Testing
Annex B refines Bacterial Filtration Efficiency testing:
- Uses using Staphylococcus aureus aerosol (3.0 ± 0.3 μm) in a 6-stage cascade impactor.
- Colonies counted after 20–52 h of incubation.
- BFE % calculated vs. control.
- BFE requirements didnt change from before. Still 95 (
Type I) or 98 % (Type II)

5/ New Annex: Rationales
The new informative Annex E provides concise explanations for key requirements, according to the authors:
- Why Bacteria, Not Viruses? The standard tests BFE with a 3.0 ± 0.3 μm droplet size, which mimics the size of droplets carrying both bacteria and viruses. Testing with bacteria yields similar results to viruses, so separate viral testing isn’t justified (I am not so sure about this one)
- Sizing & Leakage: Notes that bypass leakage affects small particle filtration, influenced by fit and breathability
- Performance limits based on expert consensus, no real gold standard publication
- Proposed Type I Withdrawal: Suggests phasing out Type I masks in the next revision due to their lower performance and availability of alternatives like community face coverings
- Shelf Life & Design: Discusses considerations for mask durability and fit variations

9/ Environmental Focus
Annex G pushes sustainability:
Encourages reuse, recycling, reduced emissions.
🌱

10/ Medical mask for source control ! 🪧

⚠️Stating SM are not PPE is not to say they shouldn't be used.
Actually the contrary, use SM first in infection control—PPE is the last resort!

EN 14683:2025 clarifies medical (surgical) masks prioritize source control to protect others from droplets, not PPE for wearer protection. Per EU Reg. 2017/745, they’re medical devices, not PPE which are governed by other (Reg. 2016/425, EN 149).

💬 Thoughts?

#EN14683 #MedicalFaceMasks #sourcecontrol #Standards #Healthcare