You may be surprised to learn that YES, Vaseline can be microwaved despite the fact that the Vaseline jar contains a warning not to microwave the product. However, it’s not an effective method of warming or melting the Vaseline.
The reason Vaseline does not heat well or melt in a microwave comes down to chemistry, so let’s dive into a quick chemistry refresher lesson.
Polar substances have a molecule on one end that is slightly more negatively charged and a molecule on one end that is slightly more positively charged.
Polar molecules change depending on the environment that they’re in.
Microwave radiation causes an oscillating magnetic field, which, in turn, causes the polar molecules to constantly change to try to keep up with their surroundings, which eventually leads to heating or melting.
Contrastingly, nonpolar molecules are evenly distributed across the molecules, making them unsusceptible to microwaves.
Vaseline is made with petroleum jelly, which is considered a nonpolar substance and therefore is not susceptible to microwaves.
While it’s not necessarily dangerous to microwave Vaseline, nothing much will happen to the Vaseline at all. It will not start a fire, create a noxious gas, or blow up the microwave.
Though it is important to note you should NOT microwave the jar or container that Vaseline comes in.
The Vaseline may feel slightly warm due to the possible presence of other ingredients used in the Vaseline formula that are nonpolar, but that will even be minimal.
In conclusion, if you want to heat or melt Vaseline, you will want to use a heating source that does not use microwaves. You could use the stove, oven, or even use the hot air from a hairdryer.