“There are processes out there that can remove 1,4-dioxane, at a high cost, so the cost of detergent will go up. Surfactant expert Brian Grady told us, “You’re going to see significant changes in because, to my knowledge, almost all of the detergents on the market today won’t pass the standards.” He mentioned a few possible consequences of the new bill.

Although the detergent companies aren’t actively putting this contaminant into their detergents, it’s unfortunately a byproduct of their formulation process. For reference, according to the Citizens Campaign test results, detergents from brands like Tide, Gain, Persil, All, and Arm & Hammer all have 1,4-dioxane levels above the limit. It will be enacted by the end of 2022, banning sales of products with trace concentrations of 2 ppm or higher, and, by the end of 2023, 1 ppm or higher. In December 2019, New York Governor Andrew Cuomo signed a bill that would “prohibit the sale of cosmetic or cleaning products containing 1,4-dioxane.” The bill came as a result of contaminated drinking water (1,4-dioxane) in Long Island. Tide Ultra Stain Release was also rated Best for Most Tough Stains by Consumer Reports. But, like our other picks, Tide Ultra Stain Release did a respectable job on most of them. (It also performed better than any other detergent on carbon, but we didn’t count the results from that stain in making our pick because we don’t think it’s as meaningful as the others.) No single detergent came out on top for all of our homemade stains.

Tide Ultra Stain Release bested the competition on most of the stain strip, removing the most sebum, cocoa, and blood, and it was second best at removing the wine (after Persil). (Ingredients aren’t printed on the bottle, but P&G lists them online.) In our testing, those extra enzymes produced visibly better results, which were also borne out by the colorimeter measurements.

And Tide Ultra Stain Release has the greatest number of enzymes of any detergent that P&G makes, a company representative told us. Surfactant expert Brian Grady (who was a project engineer at Procter & Gamble, parent company of Tide, from 1987 to 1989) explained to us that detergent prices largely reflect the number of different enzymes in their formulas. (Powder can have an especially hard time dissolving in cold-water washes.) Liquid detergent can also be used directly for pretreating stains. If you have ever started a load of laundry, walked away, and come back to find clumps of powder detergent or an undissolved pod among wet, dirty laundry, you can probably appreciate how foolproof liquid detergent is. One of their big advantages is that, unlike powder detergent and pods, they’re pre-dissolved. Liquid detergents are popular for a variety of reasons. Procter & Gamble told us that, according to a Nielsen report of sales from 20, 73% of products in the laundry category are liquid, 20% are pods, and 7% are powders. Not only did they perform better than powders and pods in our last round of testing, but they also account for the majority of what’s sold. For this round of testing, we decided to focus solely on liquid laundry detergents. There are three main types of laundry detergent: liquid, powder, and pods (called “unit-doses” by the industry, they’re also known as “packs,” “discs,” “single-dose,” or “tablets”).

Laundry detergent