Mineral oil and petroleum jelly are byproducts of petroleum production and are not used in aroma therapy. Mineral oil is used in baby oils and many commercially available moisturizers because it is an inexpensive oil to manufacture. It, however, can clog pores, prevent the skin from breathing naturally, prevent essential oil absorption, prevent toxins from leaving the body through the natural process of sweating, and I’ve read reports that it can be absorbed into the body and block vitamins from properly being utilized. These same concerns apply to petroleum jelly.