<p>If you have a giant tub of petroleum jelly in your medicine cabinet that has celebrated more birthdays than your children or pets, it is safe to say it is time to toss. Just like contact lens cases come in contact with your fingers, so does petroleum jelly (unless you scoop it out with a Q-Tip). If you have fingerprints all over that vaseline, toss and replace it with a new container. Maybe one that is smaller, too.</p>