non-soluble

It is the most non-soluble substance known to man, and therefore less likely that actually anything else in existence to be a problem?

I found a big difference between soluble (trouble for me) and non-soluble fiber (okay, within limits).

I always wonder how much of what we consume is actually absorbed, specially when factoring gut microbiome and non-soluble fibers.

Finally, the CPU thermal grease is replaced with a non-soluble foil.

It oxidizes easily, and it's oxides are heavy and non-soluble, so when it is released to the environment, it just tends to fall down and stay there.

Insects have fatty/non-soluble insides: when I turned on the wipers, I managed smears the goop more uniformly across the windshield, making visibility infinitely worse.

Then I’ve cut all simple carbohydrates or non-soluble fiber and unlike the low carb craze, increased my high soluble fiber intake from low GI whole grains like steel cut oat.

In soil it doesn't seem all that useful to accumulate toxic elements, in water I could imagine it being much easier to accumulate them into a non-soluble form that is not bio-available and can be removed much more easily.

All the ancient enzymes that use iron as catalyst use it in the form of iron-sulfur clusters, exactly like the iron that can be found in non-soluble iron sulfide minerals, so it can be presumed that the original catalysts were iron sulfide crystals alone, without the protein part that is now attached to the iron-sulfur cluster, in order to position it correctly inside the living cells.

My assumption in writing the above was that non-soluble elemental lead metal (the thing the sheathing is made out of, and that Roman aqueducts were made out of, and the thing that soil could easily trap and filter out) is the "problem" with lead poisoning; while the lead ions in lead compounds are mostly safe.