Exercise 3 solution

(a) "Chemical-free" cannot be true if taken literally. The Chemophobia article says it is "impossible if taken literally, since all consumer products consist of chemical substances". Salts, water and plant material are all made of substances (Chapter 1: matter). The label is persuading with a fear, not describing the product.

(b) "Natural, so safe" does not follow. The same page quotes a 1992 Science paper: "every natural chemical is also toxic at some dose". Safety depends on the substance and the dose, not on whether it is natural.

(c) Three questions, in the form "which substance, how much, who says so":
1. Which substances are in the salts, and which "toxins" does it remove? (An ingredient list, Chapters 4 and 5.)
2. How much of each, and how much is a dose? A percentage or a mass per serving, not "100%".
3. Who says so? Which study, how many people, compared with what? A sourced test, not an advert.
A fourth worth asking (my own addition (check)): how would a "toxin" be measured before and after?

Note: the advert is invented.