Thread: Alberta Health's procedural masks.
@AHS_media: "These masks are all safe, certified and meet ATSM Level 1 filtration requirements."
Longtime supplier PRI•MED follows ASTM F2100-11 (2011).
New supplier Vanch follows YY/T 0969-2013.
@Arfarfarf8 @mchatenay @Dave_Khan
There are key differences between the North American and Chinese standards.
ASTM Level 1 requires both Bacterial (3.0 µm) & Particle (0.1 µm) Filtering Efficiency ≥ 95%.
YY/T is silent on anything smaller than 3.0 µm.
Coronavirus average 0.125 µm.
smartairfilters.com/en/blog/compar…
Depending on the English translation, YY/T 0969-2013 requires the nose piece to be "pliable" or "plastic".
Unfortunately, Vanch took that to mean a non-pliable plastic strip in some batches, and a thin twist tie in others.
We need to see:
- AHS purchasing specification for these masks
- how Vanch was qualified as a supplier
- the test results of the pre-purchase samples
- the QC test results before release to front line
cbc.ca/news/canada/ed…
There are both logistical and health concerns with @AHS_media plan to remove the plastic wrappers from the masks here on arrival. Indefinitely.
Logistical: This is 200-500K masks/day. Who is going to unpack them, and where, to keep the masks clean?
Health: Polypropylene extrusion creates VOCs.
Which VOCs, at what levels, from Vanch's mfg process are trapped in plastic wrappers? What are the acceptable levels? What testing is being done before release to frontline workers?
brady.eu/en-eu/related-…
scielo.br/scielo.php?scr…
Get ready for more issues soon.
"They continue to try and procure other types of acceptable alternative procedural masks, including expecting large orders (in the millions) of new types of procedural masks by the end of April."
facebook.com/UnitedNurses/p…
In my 3rd tweet of this thread, I mentioned some English translations of YY/T 0969-2013 nose piece say "pliable"; others say "plastic". I accidentally posted same screenshot of "pliable" twice.
I don't have full YY/T & ASTM standards to find other differences. Has AHS done so?
AHS risking life w claim Vanch masks on Chinese YY / T 0969-2013 = PRI•MED ASTM F2100-11 (2011).
Coronavirus 0.125 µm particles aren't stopped by a 3 µm filtration standard.
Chinese YY 0469-2011 is closer, but Vanch doesn't make masks to that standard.
famisourcing.com/mask-types-chi…
Share this Scrolly Tale with your friends.
A Scrolly Tale is a new way to read Twitter threads with a more visually immersive experience.
Discover more beautiful Scrolly Tales like this.