Carol Webb's nails were her pride and joy: long, strong and beautiful.
"That was my jewel. I mean, I loved my nails," she says.
But then, like millions of other women, she decided to try an artificial alternative that promised nails that could be longer, stronger and more hard-wearing than natural nails: acrylic nails.
She visited a salon in Roanoke, Va., that was offering a full set of acrylic nails at a discount price.
Within two days, she says, she started feeling pain and pressure under her fingernails, along with some numbness. She had the acrylics removed, but then, to her horror, watched as her own nails started to turn black and come off in layers.
Webb was one of many women who had an adverse reaction to an adhesive that many nail salons use as a cheap alternative to safer nail treatments, despite a decades-old warning from the Food and Drug Administration that it is "a poisonous and deleterious substance that should not be used in fingernail preparations."
The substance, methyl methacrylate, known as MMA, makes an inexpensive adhesive that bonds very strongly and dries quickly. However, in some women it can cause adverse skin reactions wherever the nails touch, and damage or destroy nailbeds, sometimes permanently. The substance can cause nerve damage and exacerbate allergies in some women, according to Dr. Shelley Sekula Rodriguez, a Texas dermatologist who is a consultant for ABCNEWS.
The FDA first issued its warning about MMA in 1974, and most salons and manufacturers switched to adhesives containing ethyl methacrylate, or EMA, a substance that is safer than MMA but costs several times as much.
Today, six years later, Webb's nails are still short stumps that doctors say will never grow back. Ashamed to show her nails in public, she regrets the day she decided to try the salon's offer. "When you go cheap, that's what you get," she says. "And I shouldn't have done that."
Webb is now suing the salon. The salon's owners deny any responsibility.
To see whether salons are still using MMA, 20/20 investigated eight salons in Dallas, taking samples of the liquid they were using to make acrylic nails and paying to have them analyzed.
The results were alarming: The samples from all eight of the Dallas salons contained extremely high levels of MMA. In a similar test last year, 20/20 found that 14 out of 26 salons in Phoenix, Boston, Houston and Dallas were using MMA.
When confronted with the results, most of the Dallas salon owners claimed never to have heard of MMA. Inspectors from the Texas Cosmetology Commission, which regulates nail salons in the state, say that is unlikely, since manicurists are taught about MMA in the courses required to get a license.
Some of the salon owners blamed their suppliers, saying they did not know what was in the adhesive they were buying. But 20/20 tested a bottle of the adhesive from the supplier used by most of the Dallas salons, and found no trace of MMA.
Health officials believe believe that many nail salons buy the inexpensive MMA on the black market and transfer it to bottles purporting to contain the more expensive, safe adhesive.
Watch Out for the Sharp Smell
Not everyone who is exposed to MMA has an adverse reaction, and some manufacturers say the chemical is no more dangerous than other nail products. But the Nail Manufacturers Council, an industry group, supports the FDA warning and advises salons to use EMA-based products instead.
Although 30 states have banned the use of MMA in nail salons, state inspectors say enforcement is generally lax, in part because of the high cost of testing for MMA.
However, there are warning signs that can help women avoid the potentially dangerous substance.
If a salon is offering very inexpensive acrylic nail treatments, for less than $20 a set, that might be a sign that they are using the less expensive MMA. Another sign is the substance's pungent, bitter chemical smell, which can be strong enough to make one's eyes water.
MMA adhesive is so powerful that it makes acrylic nails extremely hard to remove once they have been applied. "If it takes a half an hour of soaking in really strong remover to pull those old acrylics off, she should have a high suspicion they're using MMA," says Rodriguez.