Also called “liquid petroleum,” “paraffin oil,” and “white mineral oil,” mineral oil has long been used in a number of industries, including biomedicine, veterinary medicine, mechanical, electrical, and industrial. Nowhere is its use more debated, however, than in the cosmetics industry. Used to be mineral oil was a popular moisturizer in skin and hair products. People have relied on it for decades, and things like baby oil and Vaseline are old favorite applications. But lately, this ingredient has gotten a lot of bad press. What’s the problem?