I've been adding a pinch of borax to my green tea for awhile. I believe it is a tip I read from Ted. Helps neutralize the fluoride in green tea. If I take a bath, I also add borax (for fluoride) and sodium thiosulfate (for chlorine) to the water before getting in the tub. I had had no adverse affects to either practices.
Heavy Metal Poisoning
Most borax I buy is a B.P. grade and a U.S.P. grade borax from a chemical supplier. Those are grade are often used that are pharmaceutical grade. However, those that are gotten from natural sources (e.g. borax) and go relatively unprocessed, that is unadded of additives or anything are often labeled 100% Sodium tetraborate or Borax. Without anything else.
My experience is that free heavy metals found in these product found in supermarket, are not as high as those found in more processed foods (baked goods are off the charts with me) and tap water we usually drink (my toxic heavy metals come from the drinking water and rice cooker), or even in more Organic foods and fertilizers which is very high in heavy metals.
Most contaminants from the products I used are heavy metals and they often come from frying pans, aluminum tea pots, aluminum rice cookers, iron pots & pans, or foods that has gone through a lot of processing such as fast food and chocolates, for example. Even Diet Coke is actually very toxic to me, if I have all the appropriate diagnostic devices to find out people will know the real source of toxicity which is from the benzene (sodium benzoate), bisphenol A (plastic degenerates into a pseudoestrogen Bisphenol A) and aspartame (degrades in the body to formaldehyde) and causes me to be diabetic and other sickness- long term ingestion may be more permanent).
I have actually been offline for almost a week being quite sick of neural disorder, from accidentally ingesting this product hidden in some foods they actually have added in the food at a restaurant (aspartame, sometimes they hide in coffee, but they do not REQUIRE LABELING - secret formula and GRAS status of aspartame), but never have I experienced any sickness from the use of supermarket borax or sodium carbonate labeled at 100%.
I actually have a dithizone tests and other tests of heavy metal to check for presence of mercury, lead, cadmium, iron etc. and most of the problems I have encountered came more from fertilizers, tap water, insecticides, water filter, certain pots and pans (cadmium, iron, aluminum).
The reason for all the fear of chemicals and legal disclaimer is that the seller is not given permission by the government for internal consumption even IF THE products are ACTUALLY SAFE if we actuall DO THE CHEMICAL PURITIES TEST.
If people have the money to bother to do the impurity tests a lot of people will be surprise to find that quite often the opposite is true, most processed foods and processed water, drinks, etc. are actually more contaminated. I have seen pools of aluminum found in baking goods (they create a sort of electrolysis and the aluminum ends up in the bakery products, baked goods, whenever an aluminum foil is used. People are sick simply just preparing coffee and tea in aluminum tea pots. I have actually found a simple way to check by using a small laser pointer pointing in these liquids and see tyndall effect (which are like rays of light you can see when you drive headlights in a fog). The clearer the rays, the more contaminated is the boiled water. So I tend actually to worry more about processed food than I do getting borax, or sodium carbonate from the source.
The other reason why I don't worry a lot from their uses is I always take EDTA, or no sugar no milk Green Tea to remove whatever heavy metals I consumed, which is quite often from the office water tank, rice cooker, and other processed foods, rather than sources from natural borax. This is a very slow learning process for most people to unlearn what they have geen taught and I think it is going to take many decades not years for general consumer to realize this fact. I am not entirely optimistic that people will realize this unless they bother to do their own chemical analysis and get the facts straight. The SYSTEM as we know it is a monopoly on medicine and they don't want people to stray off this area, even if THE SYSTEM doesn't work.
In general, if I cannot get USP grade, Food Grade, or Analytical Grade borax, I usually end up having to purchase those found in supermarket. I have little choice. I never tell anyone what to buy, it must be noted that I only tell myself what I can or cannot buy. What you do buy, you just have to decide for yourself. There's a good reason for that, different countries has different standards. However, my own take on the problem is they are relatively pure for most purposes since the quantitities used is actually quite small, such as 1/4 teaspoon per liter of water, so whatever contaminant in the parts per million is reduced fractionally of that amount to multibplied by .001 (about 0.1% percent) of whichever value of contaminant.
It must be noted that a lot of remedies I used is almost like 16th Century medicine and obviously 21st century products isn't selling anymore or hard to find. Therefore much of the decision, ulimately depends on you. If you want an authoritive figure to decide instead of you (if you trust him but I don't), then it is likely they will not recommend any natural remedies I post. Unfortunately for them, their treatment is actually killing me several times over, and I ended up saving my own life without much help from anyone else. That's at least my experience, perhaps, I am unlucky to rely on them.