Stomach Acid Dissolves Razors

The chemical environment inside the human stomach is so powerful that it rivals industrial-grade acids. This unforgiving bath of hydrochloric acid, which maintains a pH between 1.5 and 3.5, is capable of breaking down not just tough foods, but even metal. When an object like a steel razor blade is introduced, the acid begins a chemical reaction, corroding the metal and dissolving it into its component salts over the course of several hours. This is the same fundamental process used industrially for "pickling" steel to remove impurities from its surface.

The astonishing feat is not that the stomach can dissolve metal, but that it avoids dissolving itself. To protect against this potent acid, the stomach wall is coated in a thick, bicarbonate-rich layer of mucus that is constantly being regenerated. This biological marvel was first observed in detail by army surgeon Dr. William Beaumont in the 1820s. Through a permanent hole in the stomach of a patient, Alexis St. Martin, Beaumont conducted pioneering experiments, dangling bits of food and other substances into the stomach to witness the sheer power of digestion firsthand, laying the foundation (Review) for our modern understanding of the process.