Jessica Alba's Honest Company is recently facing another lawsuit. This time, it's for including a chemical in their laundry detergent that the company has vowed to never use.

According to INC, an investigation by the Wall Street Journal led to the discovery of sodium lauryl sulfate (SLS) in the laundry detergent by Jessica Alba's Honest Company. An Illinois resident has filed a class-action complaint against the company on Mar. 17.

Stacy Seed, the complainant, alleged that the company is "misleading [consumers] in the extreme" as they advertised their products as SLS-free. The lawsuit stated that Seed purchased Honest products that contained sodium coco sulfate (SCS), which is believed to be a safer alternative to SLS.

However, the WSJ investigation revealed that Jessica Alba's Honest Company does contain SLS. Apparently, SCS is a blend of chemicals that includes a significant amount of SLS. A common cleaning agent, SLS creates lather and has been known to irritate sensitive skin.

"Despite providing the Journal with evidence to the contrary, the Journal has falsely claimed our laundry detergent contains Sodium Lauryl Sulfate (SLS)," Jessica Alba's Honest Company wrote on their blog. "At Honest, we use Sodium Coco Sulfate (SCS) in our detergent and multi-surface cleaner. In fact, the Journal never even tested for SCS."

The company insisted that SCS is "less irritating and safer to use." Their products, from skin care to cleaners, reportedly use SCS instead of SLS.

"We feel it's important to share with you accurate information about the ingredients we choose to use in our products and why," they continued. "We also want to dispel the myth that Sodium Lauryl Sulfate (SLS) and Sodium Coco Sulfate (SCS) are the same."

Quartz noted that Johns Hopkins University environmental chemist Alan Stone explained that the structures of SLS and SCS "are exactly the same." Stone speculated that SCS was invented to make it seem "less chemical" and "more friendly."