Is Walmart's bottled water harmful because it contains calcium chloride? No, that's not true. The mineral compound is present in thousands of foods, from potato chips to tofu, in small amounts. The Food and Drug Administration (FDA) classifies calcium chloride as "generally regarded as safe."
The claim appeared in a post (archived here) where it was published on Facebook on April 25, 2019. It opened:
"Don't drink that wal mart water."
This is what the post looked like on Facebook at the time of writing:
Keishanna Weiss 😳😮Posted by Chantel Dior' Neverson on Thursday, April 25, 2019
(Source: Facebook screenshot taken on Mon Jul 20 18:42:17 2020 UTC)
The FDA gave approval for calcium chloride as a food additive in an April 1, 2019, regulation as long as the product lists it on the label. Walmart's Great Value house brand of purified water's label lists less than 1 mg of the calcium salt and 0% of the required daily minimum on its label.
The ingredient is regarded as safe across the bottled water industry. Popular sports drink Powerade, Smartwater, Nestle's Pure Life, Callaway Blue Spring Water, and Crystal Geyser Spring Water among others have trace amounts of it along with magnesium sulfate and sodium bicarbonate to add taste to the water.
A TIME Magazine article explains the use of mineral salts such as calcium chloride for flavor.
None of this should be cause for health concerns, says Marion Nestle, professor of Nutrition, Food Studies, and Public Health and professor of Sociology at New York University. The additives being put into water are those naturally found in water and the quantities of these additives are likely too small to be of much significance."
University of Idaho Prof. Bob Mahler told TIME, "If you had pure water by itself, it doesn't have any taste. So companies that sell bottled water will put in calcium, magnesium or maybe a little bit of salt."
Water with trace amounts of mineral salts are "very safe" according to the April 14, 2016, edition of Business Insider.
The magazine reports, salts and minerals, like those found in water, are necessary to help you sweat and perform other bodily functions. The water you drink, whether bottled or tap, is never just all water molecules made of hydrogen and oxygen -- no matter how pure the label claims it is. It has impurities in it.