This Halloween, Chipotle Mexican Grill hopes to scare up sales and raise public awareness for unnecessary food additives at the same time.

Chipotle’s 2015 Boorito fundraiser, an annual Halloween tradition and Chipotle’s most popular, offers a discounted, $3 burrito item to customers who come into Chipotle restaurants on October 31 after 5 p.m. in costume. Proceeds from the day, up to $1 million, will go to support the Chipotle Cultivate Foundation.  

This year, there’s a twist to the Boorito fundraiser, designed to draw attention to certain ingredients that have worked their way into the national food system. Chipotle is asking customers to come in costumes that feature “unnecessary” components to promote the idea that there are unnecessary additives in food, says Chris Arnold, communications director for Chipotle.

“Chipotle has celebrated Halloween with Boorito since very early in its history, and while the details of the promotion have evolved over the years, Boorito has remained one of our most iconic and well-loved promotions,” Arnold says.

A cowboy wearing a scuba mask or a ballerina with a shovel are just a few examples of the costume theme, and customers are only limited by their imagination. This twist supports the company’s larger vision of serving the highest-quality ingredients versus those with unnecessary additives and preservatives found on many restaurant menus.

Artificial flavors and colors, sweeteners, highly processed ingredients, and other items have come under fire from the limited-service restaurant this year, with several brands committing to removing them in the coming years. Along with Chipotle—which has largely removed genetically modified organisms (GMOs) from its food supply, along with several additives—brands like Panera Bread, Papa John’s, Noodles & Co., and Taco Bell, among others, have pledged to clean up their menus.

The movement to remove additives comes on the heels of similar movements to remove high fructose corn syrup, trans fat, and sodium from quick-service menus. With its “Food with Integrity” brand mantra, Chipotle has helped lead the industry’s charge in pulling certain additives from the food.

Arnold says Chipotle serves a menu with only 68 ingredients that are raised or grown with respect for farmers, the environment, animals, and consumers. These high-quality ingredients are then prepared using classic cooking techniques.

“This is in sharp contrast to the hundreds of ingredients—including numerous artificial flavorings, colorings, preservatives, and stabilizers—used in a typical fast-food restaurant,” he says.

This is not the first time Chipotle is challenging the ingredient lists of others in the quick-service business.

“As part of our continued effort to educate consumers on what’s in their food, we’ve released a number of entertainment-driven marketing campaigns,” Arnold says. “More recently, we’ve released two interactive games—‘Friend or Faux’ and ‘Taste Invaders’—both of which have reinforced our values through their game play.”

“Friend or Faux,” which launched in the summer, is a mobile game where players choose a Chipotle menu item and one of a number of fast-food items, then are challenged to match 20 ingredients and correctly identify which menu items contains each ingredient. And “Taste Invaders,” which launched in September, is a retro-style arcade game designed in the 8-bit style of the classic arcade game “Space Invaders.” In the game, players fire at the food additives.

“The common theme of both is this idea of giving consumers an entertaining way to contrast the simplicity of Chipotle’s food with the complex ingredient lists of many fast food items,” Arnold says.

To date, Chipotle customers have raised more than $4 million through the Boorito fundraising program to support the foundation’s work.