Bone Char: A Very Effective Filter

Bone Char — the name is perhaps…uninspiring, but it’s one the most underrated water filtering substance I’ve encountered.

It excels at removing fluoride from water — it can remove 90% of fluoride in some cases. It can also remove some heavy metals, radioactives, chlorine, and other contaminants from water. See a full list here.

Bone char, which also goes by the name Brimac, is created by taking bovine (cow) bones, thoroughly cleaning them, and drying them in the sun for at least 90 days. (Note: This isn’t a vegan product, but it is usually Kosher certified.)

The bones are then heated 1472° F in the absence of oxygen.

The result is a char made of 80% phosphate of calcium, 10% carbon, and 10% calcium carbonate. It has a very porous ionic surface, that loves adsorbing things.

Bone char is different from activated carbon in that it contains both a carbon surface area and mineral hydroxyapatite lattice surface area — see graphic below.


A couple of tips for using Brimac:

  • Brimac works best at a slightly acidic pH and may not work as well with hard water
  • If your only aim is to remove fluoride, the efficiency of the fluoride adsorption adding pre-filters to remove heavy metals and other contaminants before exposure to the bone char

You can purchase Bone Char in bulk from BuyActivatedCarbon.Com. I went ahead a bought a 6 pounds ($53) of it for test purposes. Unfortunately, there doesn’t seem to be a way to buy smaller quantities.


To filter water, I put the Brimac in a small satchel and let it sit in water overnight in a water dispenser (picture above). I also have some Japanese binchotan charcoal in there too (see my article on binchotan).

You can also find manufactured Brimac filters on Amazon.