Is it safe to add peppermint oil to your laundry, to "turn your clothes into a natural mosquito repellent?" No, it is not: Putting peppermint oil in your washing machine may pose a fire hazard.
The claim appearead on TikTok (archived here) on June 24, 2023. The video shows a screenshot taken from Twitter that explains the alleged benefits of using peppermint oil.
The text reads:
When you do your laundry, putting a few drops of peppermint oil in your load will help your clothes repel insects like mosquitoes and cockroaches...
(Translation from Japanese into English by Lead Stories staff).
This is what the post looked like on TikTok at the time of writing:
(Source: TikTok screenshot taken on Tue Jul 4 00:02:58 2023 UTC)
While peppermint oil is often proposed as a natural bug repellent, it is not clear if it actually works or how long the effect would last.
There have been reports and voices of concern about the potential fire hazard when adding peppermint oil to the laundry in drum-type washing machines with built-in dryers as oils are flammable and can ignite at certain temperatures, under specific circumstances. The manufacturer of the peppermint oil shown in the video, Kenei Pharmaceutical, has responded to these concerns by conducting safety tests. Since most drum-type laundry machines in Japan have a built-in dryer system, putting peppermint oil in your wash can potentially cause fires even when the washing machine isn't in dryer mode.
