Overview
- Only anhydrous grades of 2-propanol have been shown to form peroxides after distillation and long-term storage.
- You can identify anhydrous grades by looking under the cap of the bottle for a seal.
- Do not cite this item for non-anhydrous grades of 2-propanol
2016 report in Chemical and Engineering News reported the results of testing of 2-propanol under various conditions for its ability to form peroxides over time. Only anhydrous 2-propanol that had been refluxed for 1.5 hours subsequently distilled was shown to have a small proportion of peroxides after 2 years.
Determining if 2-propanol bottles found in a lab are a potential peroxie-former concern requires further investigation by the auditor and this includes the following:
- Ask if the lab has distilled the 2-propanol.
- Looking at the label for indication of “Anhydrous” designation
- Carefully unscrewing the cap and looking for a seal. Sample seals are shown.
If these answer to these steps are all “No”, then the 2-propanol is not likely to form peroxides and can be ignored.