Borax, also known (most predominately in the way we’re talking about right now) as sodium tetraborate, is a boron mineral and salt that’s mined directly from the ground.
Borax is not boric acid.
Borax is acutely toxic in the same manner that salt is (in rats, it’s 4500-5000 mg/kg of body weight, which is A LOT). Ingested in moderate quantities, it causes gastrointestinal upset and nausea. Bottom line: While it may be listed as “poison” on the box, it’s only toxic at very, very high levels. (Like salt, baking soda, and even water is.)
Boron is an essential mineral that the body needs for bone building, immune function, and brain function. Plants need it to grow. But, like anything, it’s needed in small moderation. Much like salt.
Boron is found aplenty in borax. People even take borax as a supplement and swear by it (I am NOT recommending you do this). That’s a little extreme, but I use it as a gauge as to how harmful borax really is.
For me – and this is my personal determination after months of searching, wondering, and compiling information – borax is just fine to use in my household cleaning routine. ESPECIALLY as a laundry detergent. It’s also fine to use, occasionally, as a hair treatment … or even in a lotion.