C&EN ran a safety letter a couple of weeks ago regarding peroxide formation in 2-propanol:
Two years ago we experienced an explosion in our lab at the end of 2-propanol distillation. Luckily, it was a small-scale distillation. To elucidate what happened, we prepared several samples of 2-propanol and kept them on a shelf away from direct sunlight at room temperature.
Prior to this incident, we were not aware that primary and secondary alcohols are peroxidizable. We hope this report is a reminder to the chemistry community that they are and that distillation procedures should take the hazard into account. For more information, see the 7th edition of “Bretherick’s Handbook of Reactive Chemical Hazards”; Chem. Health Saf. 2001, DOI: 10.1016/s1074-9098(01)00247-7; and J. Chem. Educ. 1988, DOI: 10.1021/ed065pa226.
For more, go read the letter.