Paper straws are now a thing--and founder Christina Ramirez is taking on plastic toothbrushes, with her six-year-old company Plus Ultra, which makes toothbrushes from biodegradable bamboo. Plus Ultra debuted at 33 Whole Foods locations in December 2012. It's now in more than 300 stores across the U.S., revenue is expected to top $2 million this year--and Ramirez is working on a bamboo head for electric toothbrushes.

The idea came to Ramirez, who's 33, in 2006, when she was attending the University of California. Her class, she says, was told "to create a company that addressed a global problem." She wrote a business plan for a bamboo-toothbrush company--people throw out billions of plastic toothbrushes every year--but shelved it "to get a job in marketing, something with a 401(k)."

But the idea kept nagging her, so in 2010, she quit a corporate job for an entry-level gig at a Whole Foods Market in Venice, California, going "from wearing a suit to wearing an apron and making $11 an hour" as a cashier, she says. "It was the best decision I ever made."

Within seven months, she got promoted to a buying position and learned how products got on store shelves. She presented a prototype of her toothbrush to colleagues in 2012, and when they gave it the thumbs-up, cashed out her 401(k) and went to China to find a manufacturer.

Dentist (and FDA) Approved

Ramirez consulted with dentists to come up with Plus Ultra's wave-shaped bristle head and rounded bristles. Unlike the brush handle, the bristles, which are made of nylon, are not biodegradable. "Charcoal bristles," which are used by some competitors, "are not FDA regulated or approved," Ramirez says. "We stick to what the FDA approves."

A Simpler Seal

Unlike other bamboo-toothbrush companies, Plus Ultra does not "carbonize" its bamboo handles, a finishing process that speeds up production but increases the time it takes the brush to bio­degrade. Instead, the company seals its wood with a hydrogen peroxide solution and coats it with an edible wax to protect against water damage.

Keeping It Positive

Brush handles boast affirmations like "hello handsome" and "brush smile repeat." Because the American Dental Association recommends replacing your toothbrush every three months, Plus Ultra sells a four-pack--a year's supply--for $24, and through its philanthropic arm, the company donates toothbrushes to homeless shelters, schools, and organizations like Unicef.