Can You Poison Yourself By Biting Your Nails? Toxic Chemicals Abound In Most Brands Of Nail Polish

Onycophagia, an obsession with biting nails (either fingernails or toenails or both), is a surprisingly common condition. An epidemiological study found that 1.5 percent of adult men and 3.4 percent of adult women had a history of biting nails so often as to cause visible disfigurement. More than just a "nervous habit," nail biting causes are associated with identifiable problems in the reward system in the brain, and when people not only bite but swallow fragments of their nails, there can be digestive problems. More commonly, however, the most serious physical consequence of biting nails occurs in people who use nail polish, which often contains one of more of three toxic compounds.

The Toxic Trio in Nail Polish

The Environmental Working Group tested over 100 brands of nail polish for toxic chemicals in 2005. This study found that five brands contained formaldehyde resin, eight brands contained formaldehyde, 37 contained toluene, and 89 contained dibutyl phthalate. Each of these chemicals causes serious concerns.

• Formaldehyde resin and formaldehyde are preservatives (they're used in embalming bodies at the funeral home) that also harden the nails and keep polish from chipping. A known carcinogen, formaldehyde can cause sneezing, wheezing, headaches, fatigue, dizziness, and immune dysregulation. Both products are banned in nail polish in the European Union but permitted in the USA.
• Toluene is a clear, colorless liquid that is used as a paint thinner. It helps nail polish spread more smoothly and to dry faster. It doesn't stay on your nails once the nail polish dries, but it's very volatile and can be breathed in while the polish is being applied. Toluene can cause sore throat, headache, dizziness, and fatigue, and in large amounts it can interfere with reproductive organs, the liver, and the kidneys. Like formaldehyde, toluene is banned in the European Union but permitted in the United States.
• Dibutyl phthalate is common chemical used to make plastics. It's also found in paint, pesticide, and numerous personal care products. In nail polish, it's added to make nails shiny. It is also associated with disruption of the production of reproductive hormones, as well as birth defects. This chemical is banned in the European Union but permitted in the United States.

The silica added to make a matte nail polish is relatively non-toxic.

How Can You Find a Non-Toxic Nail Polish?

Even in Europe, there are no completely chemical-free brands of nail polish. In the United States, in the ten years since the initial report, the Campaign for Safe Cosmetics has persuaded two companies to make safe nail polish, OPI and Sally Hansen. With other brands, the problem is that some companies label their products toxin-free that aren't, and other companies don't label their products as toxin-free but they are.

READ How To Stop Nail Biting And Other Nervous Habits

When the State of California tested nail 12 brands of nail polish for formaldehyde, toluene, and dibutyl phthalates, they found that:

• Color Luscious nail lacquer and
• Zoya professional nail lacquer

claimed to be toxin-free and actually were. On the other hand, the chemists also discovered that:

• Cali nail polish thinner,
• Essie Starter Wife 596 nail lacquer,
• OPI Bithday Babe nail lacquer,
• and Out the Door Topcoat

didn't claim to be toxin-free but were. Every other brand tested had one, two, or three of the most dangerous known chemicals.

Health Problems Caused by Biting Painted Nails Are Not Limited to Chemical Toxicity

The truth is, exposure to the three toxic chemicals most commonly identified in nail polish is more of a problem for nail technicians than it is for nail biters. Even if you live in Europe, where nail polish doesn't contain the offending chemicals, there are numerous other health issues associated with biting nails.

1. Nail polish remover is more toxic than nail polish. If you get enough nail polish remover into your system that you have a lingering sweet taste in your mouth, you need to get to an emergency room. Do not induce vomiting, which can make the problem worse. Acetone in nail polish removal pads can cause severe, but treatable neurological problems in infants and toddlers who put them in their mouths.

1. Nail biting can cause inflammation of the nail matrix, leading to disfigured, "dystrophic" nails. These permanently malformed nails have bumps, depressions, and ridges. Biting can also damage the cuticle and dry out the nails so that they crack and peel.
2. HPV, the same virus that causes genital warts, can easily infect the hands of nail biters. Because there are small breaks in the skin underneath the nails, the warts spread quickly from finger to finger. Warts on the hands and fingers are distressing socially and professionally, and can increase the anxiety and agitation that drives the nail biting habit. Nail biting is especially associated with HPV in women.
3. Biting the nails can cause painful, pus-filled staph and strep infections. Certain kinds of anaerobic infections can cause a condition superficially similar to gangrene, which requires the doctor to remove tissue. Not just the nail but even the finger can be lost.
4. Yeast infections of the nails are common both in people who bite their nails and in people who get manicures or pedicures too often. Even if the skin is not broken, chronic manipulation of the nail changes the cuticle so yeast can grow and cover the interior of the nail. The nail can turn black, gray, or brown, or a yeast crust can grow at the tip of the nail, looking a little like dried mucus that can't be washed away. Raised, yellow malformed nails on the hands or the feet can also result from yeast infections.
5. Dental problems can result from biting your nails. You can chip off the edges of your front teeth, or even break a tooth. Bacteria under the nails can also cause gum infections. 
6. Jaw pain is not unusual in people who bite their nails all the time. Temporomandibular joint (TMJ) pain sometimes is resolved by treating nail biting.

Most children and teenagers bite their nails at least occasionally. It's a habit that usually resolved itself by the age of 18. When nail biting becomes a problem, there's no magic nail biting cure, but one reliable remedy is to have the nail salon apply acrylic nails. Acrylic is hard to bite. As you overcome the problem, you can have your nail technician gradually reduce the thickness of the acrylic as you make the transition to gel-polish or natural nails. 

READ Habit disorders: How to prevent and treat nail biting

It's also possible to apply over-the-counter cuticle oil and bitter-tasting nail oils to discourage putting nails in the mouth. Use these products at night before you go to bed, first thing in the morning, and every time you wash your hands.