Transcript for Nail Salon Health Hazards Revealed
breaking out our spies and spy cameras. First, nail salons. You'll look at power tools and mani/pedi, in a completely different way. Here's Reena ninan. Reporter: These days, if you want make a splash on the red carpet, you have to have your nails masterfully manicured, the glitzier the better. Just ask Katy Perry and actress zooey deschanel. And just this week at the oscars -- Lupita nyong'o got as almost as much praise for her Polish as her performance. But before you try and bedazzle your fingers and toes -- It's really not about the glitter and the Polish anymore. Reporter: Listen to the warnings from this industry insider. What do you think is the one thing that nail salons just don't want the consumer to know? There is danger lurking everywhere. The potential for infection is greater than people realize. Hi, Joan. Reporter: A salon owner and nail tech for 34 years, Athena Elliot rates other salons for her website. She says they aren't necessarily safe because too many salons take shortcuts. It's a lucrative business. We are a $7.9 billion industry, and unfortunately, there's a lot of money to be made at your cost. Reporter: What have you seen? Dirty tools, dirty tubs. That's the one where I really cringe a lot. Reporter: She cringes not only because it's gross, but because it's also potentially dangerous. Possibly living inside those whirlpool tubs, fungus, E coli and other bacteria. That can cause cuticle infections, finger herpes, staph, mrs and more. Reporter: Jennifer Schnipper of palm beach, Florida, where sunshine meets sandals says this salon is clean. But at a different one she had a frightening experience. One day she developed a little blemish on the middle of her shin, pretty soon it wasn't so little. I was in extreme pain, I couldn't walk. It was hot to the touch, it was red, it was bumpy. Reporter: So, she went to the doctors. The first question she said to me "Was how often do you get pedicures?" Reporter: She knew right away? She knew right away. And she said "I guarantee you this is a microbacterium infection that you get from pedicure spa baths." Reporter: The bacteria had spread into her muscle, the only way to get rid of it was to literally cut it out of her leg with emergency surgery. Reporter: I mean, it's like a crater in the middle of your shin. Jennifer sued the nail salon and received a $375,000 settlement. What would you like to say to the owners of that salon? It's their responsibility to keep us safe and you know, they took shortcuts at my expense. Reporter: You paid with your leg, literally. But to find out the dirty truth for ourselves, "20/20" used hidden cameras in glasses, purszs, even a water boltle. To document any germ-spreading stunts. Like this. Check out this woman as she takes the cotton ball with nail Polish remover -- uses it on her own nails -- and then the same one right on us. That is how we can impart bacteria on people. Reporter: Watch as she grabs this old nail buffer, what looks like white chalk is probably someone else's dead skin. Without hesitating she uses it on us, a major no-no. Those devices are one-time use only, according to state regulations. But is really so bad that everything must be cleaned and disinfected? We swabbed, and swabbed and swabbed all over the salon and sent it to the lab. In one footbath, they found, 28 million bacteria from feces. And on a pedicure towel, staph. If you have a break in the skin that is one way that staph can get into there by using that towel. Reporter: But worst of all we found salons using illegal instruments. Is that a nail tech or a ninja? Look at the way she's slicing and dicing those callouses with a razor, called a credo blade, but its banned in at least 45 states. That type of thing is really meant for a doctor to use, not for a nail technician to use. Reporter: That semisurgical tool can cause bleeding. Yet, we found it readily available in nail salons. That;s nothing compared to what Athena has seen and experienced. She too goes undercover. Probably going to have unprotected nail sex. Reporter: Complete with a wig and a special something extra. These are spy glasses. Here she is getting a pedicure when the employee busts out a home improvement tool to -- well "Improve" -- the condition of her feet. She said, I have the perfect tool. Reporter: That perfect tool -- a dremel. A rotary device meant to drill and sand wood. But definitely not someone's foot. She pulled it out and said, "Don't worry. Don't worry, you know, I can do this for you." And really, basically, freestyled on my feet. Reporter: What did you think when they pulled out that sander? I was a little bit scared actually. Then I started to think, wait a minute, that's the same pad that was used on the person before me, and probably 20 people before me. Reporter: Ugh. That's just so disgusting. Was that it? A one-time occurence? Nope. When we visited that very salon a week later we saw the staff going Tim Allen with that dremel tool. It's always ready when you need it. Reporter: We went inside for answers. I'm Reena ninan with ABC's "20/20." We have video of a wood sander being used on people's feet here. Why would they use that here? It's a violation of state regulations. The owner wasn't at the salon. His employee Kim denied ever using the tool. I don't use this machine. Reporter: You are not even changing the discs so whatever germs go on the next person's feet potentially. When we point out that woman who was using the dremel is right next to her, Kim changes her tone saying customers like it. They want to sand to take off the dead skin. Reporter: But you know this isn't an approved device. It's used for sanding wood. And you are putting it on people's feet. If I can't use this then I stop it. Reporter: You are stopping it as of today. No more. Reporter: While she says she did no wrong, Kim promises to stop using it. So, how do state regulators deal with nail salon violations? We followed along with Joanne Ayotte, an inspector with the Arizona state board of cosmetology. Just here to do a routine inspection today. Reporter: Some like this one, clean. Others not so much. This one has been used over and over again. It would have to be discarded. I'm seeing a loft grime in here. Reporter: And the pedicure tub in this salon, downright nasty! If the client came in contact with this, germs could be transferred if they open pores that cut into skin. Reporter: That salon had multiple violations, but the inspector doesn't have the authority to shut them down. This salon owner, who says he has since cleaned up his act, will probably get a $250 fine. So many salons they just get slapped on the wrist by our state, they get fined and then they just start up again. Reporter: Athena wants everyone to know that there are also good nail salons out there too, and has a bit of advice, don't be fooled by the sticker price. Are you safer in a five-star salon that charges five-times the price? Absolutely not. Dirty knows no prejudice. It's everywhere. And it doesn't matter if you are paying $50 for a manicure, or you are paying $10 for a manicure, it's still lurking. I'm rethinking my weekly manicure. Before you get your claws out, we have some tips for you, how to make sure your nail salons. Go to our website. David and I will be right
This transcript has been automatically generated and may not be 100% accurate.