From:
James Kaufman <jkaufman**At_Symbol_Here**LABSAFETYINSTITUTE.ORG>
Subject:
Re: [DCHAS-L] Peroxide strips and 2-propanol
Date:
Oct 3, 2025 19:20 UTC
Reply-To:
ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID:
<CAHk9oERYX7Yvgkmx0OY1pUsP+kQ2FS9FUD3k1p=bM2m-1FPT4A**At_Symbol_Here**mail.gmail.com>
In-Reply-To:
<CAOCg_ca7=fRTk3Q_rfa-awZufUtffZa+m1OYhds_gqoKGjv8vQ**At_Symbol_Here**mail.gmail.com>
Isopropyl alcohol is a known peroxide former.
Several years ago, a professor was having his students do a fractional distillation of IPA and toluene. After several of the boiling flasks had exploded after the toluene was gone, he stopped the experiment. And wrote to C&EN. Michael Heylin the editor at the time replied that IPA has been known to be a peroxide former for many years. ... Jim
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I 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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