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From: Luis A Samaniego <l-samaniego**At_Symbol_Here**NORTHWESTERN.EDU>
Subject: Re: [DCHAS-L] Input on chemical incident
Date: Feb 12, 2024 15:25 UTC
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID: <CH3PR05MB10003283FD0E4B3A32ED9343696482**At_Symbol_Here**CH3PR05MB10003.namprd05.prod.outlook.com>
In-Reply-To: <CAEiU9vDARJQXXf+jS4nK=uLxY-fSqjV_56m+NRS0V+n=8aUK9w**At_Symbol_Here**mail.gmail.com>
Hi Alex,
You can also use vented caps.
One example is the URL link below:
https://www.calpaclab.com/vented-caps/
Best,
Luis.
Luis Samaniego, CIH, CSP
Sr Laboratory Safety Specialist
Northwestern University
Research Safety (RS)
345 East Superior Street
15th Floor, Suite 1522
Chicago, IL 60611
l-samaniego**At_Symbol_Here**northwestern.edu
(312)503-8300
From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
On Behalf Of Jonathan Dannatt
Sent: Thursday, February 8, 2024 5:56 PM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: Re: [DCHAS-L] Input on chemical incident
Hey Alex,
Thanks for sharing.
It sounds like everyone was safe after this incident, which is wonderful. Unfortunately, I don't have any exact data regarding this mixture, but I wouldn't expect polymerization without other material.
A possibility to consider though: Methanol and ethyl acetate are both relatively low boiling solvents (64 C and 77 C, respectively). While I doubt conditions were such that they would boil, mixing solvents can be (and often is) an exothermic
process. This will raise the temperature of the mixture which increases the vapor pressure. With an extremely small headspace, even a small increase in temperature and vapor pressure could be sufficient to cause an issue like what you described. To test this,
you can ask the lab to measure the change in temperature when the components are mixed at a smaller scale.
Some things I would suggest and love to hear others input on (specifically on point 2):
1) Like you said, waste containers should only be filled up to 80% to allow for sufficient head space.
2) If large amounts of a liquid are added together quickly, (say 2L of ethyl acetate added to 1.5 L methanol), the waste container should not be immediately sealed. I personally would cap it with a loose cap for a few minutes to allow time
for the solution to form and cool.
Again thanks for sharing : )
Best,
Jonathan
On Thu, Feb 8, 2024 at 4:24 PM Alex Hagen <fischera**At_Symbol_Here**uw.edu> wrote:
