Owners of Vitamix blenders — the expensive pulverizing machines adored by foodies and celebrities, and used by Starbucks, McDonald's, and Jamba Juice — have taken to the internet over the past year to complain of a mysterious substance coming from the machines' signature angled blades: tiny black particles.
"O-ring tiny abrasions leak into my smoothie!" noted one Amazon review. "Not sure what it is but I'm guessing this isn't the spontaneous generation of vitamins," quipped another on YouTube. "I find it quite irresponsible that they keep selling these defective blades and making their customers (women and children and babies) eat black plastic," said a post on Slickdeals.
The shards are made mostly of polytetrafluoroethylene (PTFE), the non-stick chemical more commonly known as Teflon, the company told BuzzFeed News.
The PTFE flecks apparently come from a seal at the bottom of the containers used in all blender models, Scott Tennant, director of communications at Vitamix, told BuzzFeed News. PTFE "has been used in pots and pans and other cookware for more than 50 years."
The flecks also contain about 2% graphite, which gives them their black color, Tennant said.
Vitamix conducted an internal analysis late last summer, then contracted an independent standards company to conduct similar tests. Vitamix has not published any of these scientific results.
Vitamix sold 1.4 million blenders last year, typically retailing between $400 and $700.
Though news of the mysterious "black dust" has set many customers into panic mode, ingesting PTFE is not harmful, according to independent health experts.
The reason PTFE works so well as a non-stick coating is because it's chemically inert: Nothing reacts with it. So if the particles are indeed PTFE, as the company claims, then there's nothing to fret about, experts say.
"It's unsightly, and not many people want to have the visual of having black flakes in your food," Edward Boyer, director of toxicology at the University of Massachusetts Medical School, told BuzzFeed News. "But it's probably better for you than eating a cheeseburger every meal."
Since last spring, angry customers have been posting evidence of the tiny particles, which become visible if you run the machine with water inside.
"BEHOLD... Very Expensive Black Dust," wrote one customer above this photo.
Vitamix is working on a new, shard-free model.
"We are working toward possible modifications to the seal that we hope to have in place later this year," Tennant said.
The company will not be recalling the old models because the flecks don't pose any safety risks, he added. "We do care very, very deeply about customer preferences," he said. "This was not a safety issue."
It is true that pure PTFE is usually safe. The exception is when PTFE gets very hot — above 500 degrees Fahrenheit — and turns into vapor. People who breathe in these fumes, such as workers who mill PTFE, can get chills, fever, and respiratory distress.
Vitamix machines produce a lot of heat: The blades spin so forcefully that, after running for several minutes, it can heat the contents of the container, making hot soup. But that's not enough to vaporize PTFE.
"The good news here is it's very, very difficult for household equipment to heat up to the point that it can vaporize PTFE," Boyer, the University of Massachusetts toxicologist, said. "Unless you've got a burning Vitamix mixer, you're not going to have a problem with it."
Vitamix has offered some customers replacement machines, but many complain that the replacements produce the same particles.
Some customers are frustrated by the company's lack of transparency about its investigation.
Linda Newnham, a Vitamix customer from Hobart, Tasmania, first learned of the black flecks last October, when someone posted about it in her Vitamix Facebook group. She reached out to Vitamix Australia and Vitamix U.S. several times, by phone and Facebook message, and company representatives told her they were aware of the problem but didn't have any answers.
"I also posted comments on Vitamix US Facebook page asking for information about the black specks which were just ignored!!," Newnham told BuzzFeed News by email. "I was quite surprised that a company with such a good reputation had such a bad customer service!!!"
A few months ago, Steven Palmer, an attorney from Cleveland, Ohio, was searching online for a new container for his Vitamix 5200. He came across several of the YouTube videos showing the black dust, then discovered that his own machine made it too.
Palmer sent the company a message through its website: "I am worried that I may be ingesting something harmful. Can you let me know what this is, and how it can be fixed?" A few days later, a customer service representative acknowledged the problem and explained that the flecks were PTFE. Palmer wrote back again, asking more about safety concerns. But the company did not respond.
"We got the machine to make baby food," Palmer told BuzzFeed News. "They haven't given a satisfactory answer from my perspective."
Despite his frustration, Palmer hasn't ditched the machine. He's using the powerful Vitamix base with a different container, made by Waring Products, one of Vitamix's main competitors. (The first Waring container he tried made the same black flecks, but the second one, so far, is clear.)