Clean IQ: What’s Really in Those Tide to Go Pens? And Why Don’t You Have to Rinse Them?

Welcome toClean IQ, where we uncover the chemistry of common life and explore the science behind your favorite cleaning solutions.

My husband, bless his heart, has the hand-eye coordination of a very drunk raccoon. If there is a thing to spill on or tip over or dump out within roughly 20 feet, he will find a way to do it. I wish I were exaggerating, but literally as I was writing this, he maneuvered tomato sauce from the pan onto his new shirt. Consequently, I have become something of a Tide to Go fairy. But how do these mystifying, marriage-saving pens actually work? What’s going on inside those wizard sticks?

The Tide to Go Instant Stain Remover pen是一种便携式、detergent-based highlighter-like年代tain removing stick that lifts and “erases” common stains without the need for washing or rinsing.

The magic of the Tide to Go pen lies in its portability, its jaunty, go-anywhere attitude. If you were, say, taking tea with Meghan Markle and splooshed some jam out of your crumpet and onto your white fascinator, you could discretely excuse yourself to take care of your royal mishap. Stain removing pens are often a far better solution than soap and water—depending on the temperature of the water and the makeup of the fabric, you might cause the stain to run or set (and unless you have a backup fascinator hiding in the glovebox of your Aston Martin, you’re SOL).

According to Jennifer Ahoni, Procter & Gamble’s Scientific Communications Manager for Fabric Care, the Tide to Go pen was developed especially for these on-the-go stains: the particular combination of detergents and surfactants were chosen specifically to work without rinsing.

“The key ingredient is hydrogen peroxide,” says Ahoni. “It breaks down the molecular structure of the pigments in the food, making the color and stain essentially disappear.” Basically, hydrogen peroxide attacks color-causing chemicals (also known as chromophores), and, by dissolving them, makes the stain appear to vanish.

If you’re wondering (like I am) why the hydrogen peroxide only reacts with the fresh stain and doesn’t, say, bleach your clothes to bits, the principle is the same as any laundry detergent: Garments are dyed and treated so as to be fairly color-fast, and the hydrogen peroxide in stain removal pens is gentle enough not to interact with the colors of your clothing. (For the record, Tide does suggest testing the pen on an inside seam if you’re concerned about colorfastness.)

Other important ingredients in your stain sword include various surfactants and detergents that grip stain molecules to help pull them from the fabric; and, crucially, water, which activates the surfactants and helps them swoosh off stains. Finally, magnesium sulfate—a.k.a. epsom salt—helps the spot dry quickly enough for you to get back to your tea.

According to Tide, 72 percent of stains that people experience on the go are the result of food and drink, and that’s what the pen was designed to attack. It works best on stains like ketchup, coffee, and wine; less so on protein stains like blood or grass. (Here’s a helpful stain removal chartthat breaks down the molecular structures of particular stains, if you’re into that kinda thing.) Additionally, Ahoni recommends first wiping the stain gently to remove any excess, and attacking the stain immediately. Once a stain is dry, you’re better off treating it when you get home with amore traditional, heavy-hitting stain removerbefore tossing it in the wash, or handing it to your long-suffering partner with a meek shrug.

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