Re: Doctors and biochemists' opinions
Look at the MSDS. This compound has an extremely low oral toxicity. From Wikipedia:
Food additive[edit]
Borax, given the E number E285, is used as a food additive in some countries, but is banned in the US. As a consequence, certain foods, such as caviar, produced for sale in the US contain higher levels of salt to assist preservation.[23] Its use as a cooking ingredient is to add a firm rubbery texture to the food, or as a preservative. In oriental cooking it is mostly used for its texturing properties. In Asia, borax (Chinese: 硼砂; pinyin: péng shā) or (Chinese: 月石; pinyin: yuè shí) was found to have been added to some Chinese foods like hand-pulled noodles lamian and some rice noodles like Shahe fen, Kway Teow, and Chee Cheong Fun recipes.[24]
I found a site that says it is used in caviar in the EU. It's gotta be safe if the ruling elite eat it and forbid it for everyone else. WTF?
I think your herbalist might be hesitant because it is found in the cleaning aisle. Call it Sodium Borate from now on.