Sodium lauryl sulfate (SLS) is an organic chemical derived from coconut oil and it is commonly found in everything from laundry detergent to toothpaste. SLS is also one of the ingredients that Jessica Alba’s Honest Co. pledges to avoid using in its products. However, a new study claims that tests turned up SLS in Honest laundry detergent — an allegation the company is now denying.

The Wall Street Journal reports that it commissioned tests of Honest detergent from two independent labs, and that both tests confirmed the presence of SLS.

One lab noted that it was a “significant amount” of the chemical, while the other told the Journal that it was “not a trace amount” of SLS.

In a blog post in response to the Journal story, Honest accuses the newspaper of “harming the reputation and good will that we are so proud to have built here at Honest.”

Honest contends that it doesn’t use SLS, but sodium coco sulfate (SCS), which it claims is less potentially irritating than SLS.

However, the Journal counters that the scientists it interviewed for the story explained that SCS “is a mixture of various cleaning agents that includes a significant amount of SLS.”

The report notes that Honest changed its “Honestly Free Guarantee” while the Journal was researching the story. The guarantee had stated that products were “Honestly free of” the listed ingredients, including SLS, but that it now states that the products are “Honestly made without” those same ingredients.

Honest does not manufacture its own detergent, but partners with a manufacturer of eco-friendly detergent. The Journal tested the detergent that company makes for its own brand and also claims to have turned up significant levels of SLS, even though the manufacturer maintains it only uses SCS.

Both chemicals are potential irritants, but have been generally considered safe when used properly.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.