Thanks Pentax, I found this link:http://www.pgproductsafety.com/produ..._threshold.pdf that seems to suggest they had to answer for 1,4 diaxane in the past. That's why I included it, though I really don't know if it exists in the product here. But I asked just in case.
Looks they are referring to trace levels of 1,4-dioxane that may be formed in the manufacturing process for a detergent. Doesn't look like they were linking this to the Swiffer dry products.