Hexachlorophene is a powerful antibacterial chemical that was once one of the most common germ-killing ingredients in consumer products, from bar soap to toothpaste. It was pulled from store shelves in the early 1970s after evidence linked it to brain damage in infants, and today it’s available only by prescription for limited medical uses.
How Hexachlorophene Works
Hexachlorophene belongs to a class of chemicals called chlorinated bisphenols. It’s made of two linked ring-shaped molecules, each studded with chlorine atoms. This structure makes it especially effective at killing certain types of bacteria.
At low concentrations, hexachlorophene disrupts the energy-producing machinery inside bacterial cells. It interrupts the chain of chemical reactions bacteria use to generate fuel, essentially starving them. At higher concentrations, it goes further and ruptures bacterial cell walls entirely, destroying the organisms outright. This makes it a potent weapon against gram-positive bacteria, the broad category that includes staph and strep. It’s much less effective against gram-negative bacteria, which have an extra protective outer membrane that shields them from the chemical.
From Hospital Scrub to Household Staple
Hexachlorophene first gained popularity in hospitals during the 1940s and 1950s as a surgical hand wash and general antiseptic. It was effective, nonabrasive, and left a residual germ-killing layer on the skin that kept working between washes. Surgeons loved it.
The consumer market wasn’t far behind. In 1948, Dial soap launched as the first consumer product to include hexachlorophene, marketing it as a way to kill the bacteria that cause body odor. Dial became the top-selling soap brand within five years. By the early 1970s, hexachlorophene appeared in over 400 personal care products: toothpastes, deodorants, feminine hygiene sprays, baby powders, and skin cleansers. One of the best-known was pHisoHex, a liquid soap widely used in hospital nurseries to bathe newborns and prevent staph infections.
The Problem With Infant Skin
The same property that made hexachlorophene effective, its ability to penetrate biological membranes, also made it dangerous. The chemical passes through skin and enters the bloodstream. In adults with healthy, intact skin, the amount absorbed is relatively small. In newborns, the equation changes dramatically.
Infants have a much greater ratio of skin surface area to body weight than adults. Their skin is also thinner and more permeable. This means that washing a baby’s entire body with hexachlorophene soap delivers a proportionally much larger dose into the bloodstream than the same wash would in an adult. Studies found that bathing newborns with standard 3% hexachlorophene soap for just three to five days produced significant blood levels of the chemical.
A landmark study of 46 premature infants who received repeated whole-body baths in undiluted pHisoHex found a clear statistical link between the exposure and a specific type of brain damage called vacuolar encephalopathy. This condition creates sponge-like holes in brain tissue, particularly in the brain stem. The severity correlated with the number of baths, the concentration of hexachlorophene used, and how thoroughly the babies were rinsed afterward.
The Morhange Talc Disaster
The risks of hexachlorophene came into sharp focus in 1972 in France, when baby powder sold under the brand name Morhange was contaminated with abnormally high concentrations of hexachlorophene. Thirty-six infants died. The tragedy became one of the most significant cosmetic safety disasters in modern history and directly prompted France to overhaul its cosmetic regulations. It also accelerated regulatory action in other countries.
The FDA Steps In
In September 1972, the U.S. Food and Drug Administration moved to restrict hexachlorophene. The agency reclassified products containing the chemical so they could no longer be sold over the counter. Any drug product with hexachlorophene now required a prescription and had to carry the “Rx only” label.
The FDA also established specific prohibitions that remain in effect today. Hexachlorophene is contraindicated on burned or damaged skin, on mucous membranes, and for full-body bathing as a preventive measure. These restrictions reflect the core danger: when hexachlorophene reaches the bloodstream in sufficient quantities (blood levels around 2 micrograms per milliliter were linked to brain damage in animal studies), it becomes a neurotoxin rather than a helpful antiseptic.
Where Hexachlorophene Stands Today
Hexachlorophene hasn’t disappeared entirely from medicine. It still appears in some reference lists of antiseptic agents used in dermatologic surgery, alongside more common options like chlorhexidine and povidone-iodine. In practice, though, newer antiseptics with broader germ-killing ability and fewer safety concerns have largely replaced it. Its role in modern dermatologic surgery is considered primarily historical.
The story of hexachlorophene is essentially a case study in how a chemical can be genuinely useful in one context (a surgeon scrubbing their hands) and genuinely dangerous in another (a nurse bathing a premature baby). The difference comes down to absorption: how much gets into the blood, how quickly, and what the person’s body weight and skin integrity look like. That distinction, obvious in hindsight, took decades and considerable harm to establish in regulatory policy.