any chemists out there

Tom Wilbur’s article in the IJ today describes hydraulic fracturing chemicals as “caustic” which by my dictionary means burning, cutting, biting, corrosive. This is not my understanding of many of the dangers of the chemicals used in fracking, so perhaps not the best way to accurately characterize them.  Nowhere in my reading of reports of the EPA study of well contamination in Wyoming is “caustic” used to describe the chemicals found. Yes some may be caustic, but this seems misleading. I am wishing someone with a scientific background would write a letter to the editor, perhaps a guest viewpoint, talking about what caustic means and why the toxic and endocrine disrupting effects of some of these chemicals are important to understand. Also understanding that parts per billion which are effective concentrations for some of these chemicals is not intuitive. You biochemist or chemist writing this letter could hit that issue too. thanks. Laurie Roe