Topical camphor absorbed through mucous membranes or broken skin also can be toxic. That's why you should never put VapoRub in or around the nostrils — especially a small child's nostrils. And if VapoRub gets in your eye, it can injure your cornea.
How much VapoRub is toxic?
Vicks VapoRub: Camphor Concerns However, camphor is also highly toxic: Eating or drinking as little as five milliliters of camphor oil can kill a child.27 Aug 2009