Definitely a very dangerous article title.... with ulterior motives I would bet. The benefits of flossing FAR outweigh any risk of any PFHxS. Definitive serious diseases (heart, lung, diabetes, cancer to name a few) have been directly linked to periodontal disease which is also directly related to failing to floss are all over peer reviewed journals. This article linked is not peer reviewed - and not even close to being worthy of it - even though the article attempts to portray itself as one by having a "fact checked" secondary name under the authors name. The author is a fashion design critique journalist who has also written an article about teeth staining associated to fluoride that also has significant false information in it. Based on this and her other article, my guess is she is anti-fluoridation - or just threw together a last minute piece to meet a deadline for her publisher. There are a lot more than just 2 manufacturers of floss who add fluoride to their floss - which is the basis of the "toxic chemical" referred to in the headline title.
Two words - FAKE NEWS