Most companies put two main surfactants in their dish liquid: sodium lauryl sulfate (SLS) and sodium lauryl ether sulfate (SLES). As surfactant expert Brian Grady explained, SLES is a modified version of SLS, and it has the benefit of creating less soap scum. These surfactants aren’t a concern in and of themselves, but when you make SLES from SLS, the reaction creates a small amount of a compound called 1,4-dioxane, which can be hazardous in high doses. Manufacturers can remove this contaminant from surfactants through a process called vacuum stripping, but some may still make it into the finished bottle of detergent. And because it’s a contaminant and not an ingredient, detergent companies aren’t required to include it on the label.
1,4-dioxane is enough of a concern that New York recently banned cleaning and personal care items that contain more than trace concentrations of it, and other states have programs where manufacturers must report if products for children contain the chemical above certain limits. But a risk evaluation completed by the Environmental Protection Agency in 2020 found “no unreasonable risks to consumers” from dish soaps that contain 1,4-dioxane as a by-product. It probably helps that dish soap is best used in small amounts, diluted with water. If you’re still worried about it, wearing dish gloves will create a barrier between your skin and the soap. (We like the Glam-Gloves Dishwashing Gloves and the latex-free Clorox Ultra Comfort Gloves.)
Phthalates—a class of chemicals known as plasticizers—make hard plastics more flexible and therefore harder to break. Phthalates are found in hundreds of products, and CDC researchers have found phthalates (or metabolites) in many people they tested, leading them to say that exposure is “widespread.” In dish detergent, phthalates tend to be used in the fragrance mixture.
The CDC’s fact sheet on phthalates says, “Human health effects from exposure to low levels of phthalates are not as clear. More research is needed to assess the human health effects of exposure to phthalates.” The FDA says that phthalates don’t pose a safety risk the way they’re used in cosmetics right now, but they’re keeping an eye on it. You won’t see anything that looks like a phthalate on the outside of a dish detergent bottle—per FDA rules, companies are not required to list the ingredients of a fragrance. However, choosing fragrance-free dish detergent will probably help you steer clear of this one if you want to. And many detergents, such as the one from Seventh Generation, tend not to use phthalates and advertise that on the label.
This article was based on reporting by Leigh Krietsch Boerner. It was edited by Annemarie Conte and Marguerite Preston.
