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From: David EldrEdge <Dave.EldrEdge**At_Symbol_Here**NALTIC.COM>
Subject: Re: [DCHAS-L] School Incident with Dry Ice
Date: Feb 29, 2024 22:50 UTC
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID: <CAFCR6ua1VwAcOjTgCGTDFVuwYGM7m_NAgV6-G7eP0aMSdqtw_w**At_Symbol_Here**mail.gmail.com>
In-Reply-To: <CAGtjs7G4U3DkSXs4nH3UWYh1KCqwZBga9YamR9Q6qA6kk=VPOg**At_Symbol_Here**mail.gmail.com>
Moles of CO2 = (2.27 kg * 1000) / 44.01 g/mol = approximately 51.53 moles
Volume of CO2 = 51.53 moles * 0.0821 L·atm/(K·mol) * 298 K = approximately 1261 liters
CO2 concentration = (1261 liters / 175,000 liters) * 100 = 0.72%
CO2 concentration in ppm = 0.72% * 10,000 ppm/% = 7200 ppm
CO2 concentration in ppm for the entire room = 7200 ppm / 2 = 3600 ppm
With the entire room volume considered, the CO2 concentration resulting from the sublimation of half of a 10-pound block of dry ice would be approximately 0.36% by volume throughout the room. This calculation assumes eventual uniform distribution due to gas mixing mechanisms such as diffusion and convection currents.Seeing as how dry ice is more dense than air and small children breathe closer to the floor, I could envision a closed room "filling up" with CO2 gas and pushing out adequate oxygen for them.some back of the envelope calculations (I hope I got all my unit conversions?.....it's been awhile since I've taught undergrads chemistry) for a 10x10x3.5 meter room, the lower half of the room's volume is 170,000 Liters.If half of a 10 pound block of dry ice sublimates (5lbs) = 51.6 moles = 1240 Liters of CO2 (using ideal gas law and room temp). That looks to me like 0.7% by volume. According to some quick googling, those levels are dangerous and can lead to dizziness, nausea and worse.--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.orgOn Wed, Feb 28, 2024 at 8:35 AM Info <info**At_Symbol_Here**ilpi.com> wrote:--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.orgI can’t think of any scenario with dry ice in this situation that would have caused this. You’d have to a significantly elevated level to feel something, at least 2,000 to 5,000 ppm, and the amount of CO2 you can bring into a classroom is what, a couple of pounds? The room would have to be hermetically sealed or you’d have to be huffing the stuff.There’s either something massively left out of this story or it’s a case of chemophobic mass hysteria (guess that’s called mass psychogenic illness these days given the misogynistic origin/premise of the word hysteria). See, for example, https://www.aafp.org/pubs/afp/issues/2000/1215/p2655.html and https://www.verywellmind.com/understanding-groupthink-2671595Similar reports have been seen in the literature, https://pubmed.ncbi.nlm.nih.gov/10631279/ and there have been cases of MPI reported at vaccination centers as well https://pubmed.ncbi.nlm.nih.gov/12814329/Rob Toreki======================================================Safety Emporium - Lab & Safety Supplies featuring brand namesyou know and trust. Visit us at https://www.SafetyEmporium.comesales**At_Symbol_Here**safetyemporium.com or toll-free: (866) 326-5412Fax: (856) 553-6154, PO Box 1003, Blackwood, NJ 08012
On Feb 24, 2024, at 7:30 PM, Monique Wilhelm <biocmst**At_Symbol_Here**GMAIL.COM> wrote:--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.orgI do not have any additional details. Although I do suggest anyone working with hazardous materials with groups (or otherwise) to do a risk assessment and have appropriate controls in place as well as plans for any incidents that could occur.