[labnetwork] Question about cleanroom mask policies

[Jörg Hübner]

Hi
At DTU Nanolab we do not allow user provided masks in the cleanroom due to the fear of particle contamination. Users have to wear a provided mask preferably before entering the corridor leading to gowning. Inside gowning a max of two persons is allowed. The combination of masks, high airflow and efficient HEPA filtering (quasi laminar air velocity is around 0.5 m/s downward) reduces the risk of infection to  very unlikely.
We have also studied the literature and have also found that single viruses do not survive ( i.e. dry out immediately) if not adsorbed to a particle or droplet. Hence HEPA filters are extremely efficient and I fully agree that the cleanroom is probably one of the safest places to be regarding infection. No regular tests of staff or users are carried out.
We have been running the cleanroom with a maximum of 50 persons inside (around 1300m2 of cleanroom) since May without infection event.
We have had one staff member, who was subsequently tested positive, working inside the cleanroom (the staff member worked possibly several days in the cleanroom while infected until he went home with syptoms and got tested). All rules  and regulations were followed (mask, distancing), nobody else got infected. This is one data point and doesn’t allow any conclusions but still it is worth mentioning (the staff member had relatively mild symptoms and was back at work after two weeks).

Distancing is a problem especially in training situations but here the high air velocity in combination with masks is helping us enormously. We are currently introducing headset intercoms (inspired by Nanolab NL in Twente, NL) for training situations. This allows training situations without raising the voice in noisy environments thereby preventing unnecessary possible emission of viruses as well as proper distance. Of course proper hygiene regarding the headsets is a must.

Best
    Jørg


Jörg Hübner, Ph.D.

Director


DTU Nanolab

National Centre for Nano Fabrication and Characterization

Technical University of Denmark
DTU Nanolab

National Centre for Nano Fabrication and Characterization

Ørsteds Place

Building 347, Room 178

2800 Kgs. Lyngby
Denmark

Direct +45 45255762

Mobile +45 22785157

jhub at dtu.dk<mailto:jhub at dtu.dk>

www.nanolab.dtu.dk/english<http://www.nanolab.dtu.dk/english>


[signature_1477035095]








From: <labnetwork-bounces at mtl.mit.edu> on behalf of Tony L Olsen <tony.olsen at utah.edu>
Date: Wednesday, 16 December 2020 at 19.16
To: Robert Vandusen <RobertVandusen at cunet.carleton.ca>, "labnetwork at mtl.mit.edu" <labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] Question about cleanroom mask policies

Robert

Early this summer, when the university began allowing folks back on campus, face masks were required.  In fact, the university even provided a multi-layer cloth mask to ALL students, faculty, and staff.  Most people use that mask, while some have found other styles.  I did not want anyone removing or replacing that mask to enter the cleanroom, so they continue to wear their own mask for the cleanroom.  Frankly, I recognized that any user-provided mask (cloth or paper) may not be very effective at particle filtering, but there are worse regular practices that compromise the cleanroom.  We only double-mask (add a standard cleanroom snood) when the user’s mask does not cover all facial hair.  I have no data to support our approach, but it seemed to be a reasonable compromise to the current situation.  The biggest problem has been the increased fogging of safety glasses.  Social/physical distancing is still promoted, but poorly practiced.

I may be naïve, but I believe standard cleanroom protocols, frequent wipe downs of workstations, occupancy limits, and the high air exchange rate significantly reduce the risk of spread even when social distancing is problematic.  Our cleanroom reopened for limited use in May, including several lab courses during Fall Semester.  To date, I am unaware of any lab member infected while using the cleanroom – although a few have been elsewhere.

tonyO


Tony Olsen
Nanofab Cleanroom Supervisor/Process Engineer
University of Utah
36 S Wasatch Drive, Suite 2500
Salt Lake City, UT  84112
801-587-0651
www.nanofab.utah.edu



From: Robert Vandusen <RobertVandusen at cunet.carleton.ca>
Sent: Tuesday, December 15, 2020 10:29
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Question about cleanroom mask policies

Hi all.
Hope this finds everyone safe.
Now that N95s are starting to become a bit more accessible, there has been some recent discussion within our labs about whether to adopt an N95 mask policy for new users and when distancing is a challenge.
So far we have just been wearing the standard cleanroom style masks.
Just wondering what other labs have been using.

Thanks
Robert Vandusen
Technical Officer, Microfabrication Lab
Electronics Department
Carleton University
room: 4184 Mackenzie Building
613-520-2600<tel:613-520-2600> ext 5761
Robert_vandusen at cunet.carleton.ca<mailto:Robert_vandusen at cunet.carleton.ca>

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