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From: Info <info**At_Symbol_Here**ILPI.COM>
Subject: Re: [DCHAS-L] Peroxide strips and 2-propanol
Date: Oct 3, 2025 19:34 UTC
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID: <4908F71A-26F8-4A6D-80AD-443C52503D72**At_Symbol_Here**ilpi.com>
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Use and Storage of Peroxide-Forming Solvents
The solvents most commonly used in the laboratory solvents, such as diethyl ether, tetrahydrofuran, cyclohexene, glycol ethers, decalin and 2-propanol are shown in Group B of the previous section. These compounds produce organic peroxides that are significantly less volatile than the solvent in which they are formed, as a result, evaporative concentration or distillation can produce dangerous levels of peroxides. In fact, most Group B solvents are sufficiently volatile that multiple openings of a single container can result in significant and dangerous peroxide concentration. The next section contains a list of key aspects to consider when handling peroxide-forming solvents.
On Oct 3, 2025, at 12:45 PM, Laurie Yoder <000022a100962bdc-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU> wrote:--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.orgI am doing a chemical hygiene independent study course with a student, and (mainly for educational purposes) we tested our 2-propanol in the stock room with peroxide test strips. There was an intense unmistakable color change, which seemed surprising given that the containers are less than 1 year old. My question is if others of you with more experience have gotten positive tests like this--can it really contain that much peroxide or is there some other interference happening with the test strips?
- The brand is "WaterWorks", not expired.
- The strip was dipped in the 2-propanol, extra drips removed, then a drop of DI water was added to the strip.
- We also tried it in reverse-adding the water first, then dipping. Same result.
- Other organics tested in this way did not indicate any peroxides.
We don't distill the stuff so I'm not overly concerned, mainly curious. What's happening?Laurie--Laurie M. Yoder, PhD (she,her)
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