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Subject: Re: [DCHAS-L] Sars-CoV2 infectivity
Date: Thursday, June 25, 2020 at 2:40:30 PM
Author: "Stuart, Ralph" <Ralph.Stuart**At_Symbol_Here**KEENE.EDU> 		Next by Date:
Subject: [DCHAS-L] Face masks and solvents
Date: Thu, 25 Jun 2020 22:37:27 +0000
Author: Jack Reidy

From: Monona Rossol <0000030664c37427-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject: Re: [DCHAS-L] Sars-CoV2 infectivity
Date: Thu, 25 Jun 2020 18:53:45 +0000
Reply-To: Monona Rossol <actsnyc**At_Symbol_Here**cs.com>
Message-ID: 620006003.3030882.1593111225714**At_Symbol_Here**mail.yahoo.com
In-Reply-To <4B902B12-5548-4AF5-8131-6600FCC774C4**At_Symbol_Here**keene.edu>


Thanks Ralph,  900 to 1000 ppm CO2 is also where documented effects on mental acuity can be shown.  It's a nice number.   Thanks for this reference.  I'll add it to the research papers I have to support this limit or the WEEL 800 ppm limit.

Monona


-----Original Message-----
From: Stuart, Ralph <Ralph.Stuart**At_Symbol_Here**KEENE.EDU>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Thu, Jun 25, 2020 2:40 pm
Subject: Re: [DCHAS-L] Sars-CoV2 infectivity

> >All I know is the PEL at 5000.  Where does this reasonable target come from?

The OSHA Technical Manual Chapter 2 on Indoor Air Quality Investigation
https://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_2.html

They actually got it from a 1987 NIOSH report, back in the good old days when "the outdoor, ambient concentration of C02 is usually 250-350 ppm." It was used a reasonable proxy for air exchange rates and noted that above 1000 ppm, increased complaints could be expected. It's not clear whether they complaints they have in mind include viral infections (the effects they note list "headaches, fatigue and eye and throat irritation are frequently found to be prevalent"). I remember those days when addressing IAQ concerns was as confusing and emotionally fraught as managing Covid issues is today.

Thanks for checking on this.


- Ralph


Ralph Stuart, CIH, CCHO
Environmental Safety Manager
Keene State College
603 358-2859

ralph.stuart**At_Symbol_Here**keene.edu

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