Starbucks is discontinuing a blending powder for drinks after particles went ‘airborne’ and left baristas coughing and falling ill

When Jasmine Leli, a Buffalo, New York-based Starbucks barista, trialed the company’s new blending powder last month, she was greeted with a plume of dust that irritated her nose and throat for hours afterward.

The powder was introduced last month as part of the Seattle-based coffee chain’s seasonal rollout of blended energy refreshers—a bright-colored, slushy fruit beverage—with the ingredient intended to help keep the drink a consistently-blended texture. (Starbucks has a line of iced refresher beverages available year-round that do not require this blending.) But pouring the contents of the package into storage containers, and then into blenders to prepare the beverage, seemed to always result in residue from the product dispersing everywhere, the barista said.

“You pour the contents of this package into this container, and it’s very airborne,” Leli told Fortune .

“It doesn’t matter what you do to try and decrease the effects of it going into the air.

It’s like a cloud.” Last week, Starbucks discontinued the blending powder from its U.S. stores.

A spokesperson told Fortune the move was part of a “regular seasonal menu transition.” At this time, Starbucks does not have plans to bring back the blending powder.

“Partners and customers can feel confident in the ingredients we use,” a Starbucks spokesperson said in a statement.

“The blending powder used in our Summer Blended Refreshers contained a small amount of food-grade silica, a commonly used food ingredient that helps ingredients mix consistently.

It’s safe for use in food and safe for use in our coffeehouses when used according to instructions.” Baristas’ concerns surrounding the blending powder Originally introduced in 2012, Starbucks’ refreshers are the second most popular drink , behind only espresso, according to the company, though it did not give a timeline for when refreshers climbed the ranks.

For nearly two years under the helm of CEO Brian Niccol, Starbucks has tweaked its menu and operations as part of its “Back to Starbucks” turnaround plan.

The company has since seen a boost in sales , including an 8.1% increase in comparable sales in North America last quarter.

The move also followed weeks of pressure and outward concern from union baristas, who reported having headaches, coughing, sore throats, and hives associated with using the product, according to Starbucks Workers United, which represents about 12,000 baristas.

Of more than 600 baristas surveyed by the union, 86% reported that they or a coworker felt sick after using the powder.

Baristas began expressing concern about the product in July shortly after its rollout.