The soaps which were studied that caused a false-positive result were: Johnson & Johnson’s Bedtime Bath, CVS Night-Time Baby Bath, Aveeno Baby Soothing Relief Creamy Wash and Aveeno Baby Wash & Shampoo. "Researchers also tested ingredients used widely in soaps and shampoos, including polyquaternium-11 and cocamidopropyl betaine, which both elicited positive marijuana test results. So far, there is no explanation as to why the chemicals interfere with the test's function, but importantly, they aren't intoxicating; they don't cause symptoms of marijuana exposure in children. The researchers think minute amounts of the substances were simply washing off the babies' skin into their urine samples and confounding the screens."
“Our findings in this study drive home the point that confirmation by more sophisticated methods such as mass spectrometry should be considered before moving ahead with interventions such as child social services or child abuse allegations, which may be false, “ said co-author Carl J. Seashore, MD, associate professor of pediatrics at UNC and director of the Newborn Nursery. “We wrote this paper to inform care providers and laboratory medicine people in hospitals that this issue is out there and that positive urine screens for THC need to be confirmed.”
This is just another reason for me to not use Johnson and Johnson's baby shampoo. A few weeks ago, I wrote a post about toxic baby shampoo. While in this instance, it does no harm to the baby, this is yet more chemicals that may cause issues (although indirectly) for my baby. I took pictures of the two bottles of Johnson and Johnson's baby wash that I had and they both contained cocamidopropyl betaine.