Quite a few months ago, I mentioned a test I thought I might run. I didn't start it at the time because it was winter and my assistants for this particular test tend to be sluggish when it's cold out. Then I forgot about it for a while.
For those who followed the link above, yes, I'm talking about that test.
Meet my lovely assistants, who will be doing the actual work of the biodegradation test! It's summer now, and they're happily eating through my kitchen scraps.
Some things are unavoidably toxic, and some things were unavoidably toxic until a new, less toxic process was discovered. Less toxic is always a good thing. Sometimes it's less expensive in terms of direct costs such as how much the reagents cost, sometimes less expensive in terms of indirect costs, such as safety precautions and environmental protection.
Sodium hydroxide is one such; the old industrial method of making it involved mercury, which is highly toxic. The new industrial method doesn't. (There are still toxic chemicals involved, but they're not mercury.)
One thing that will hopefully one day be added to the past-tense version of unavoidably toxic is gold mining. Currently, if gold can't be panned from a streambed (placer mining) where it's present as pieces of fairly pure gold, it has to be dissolved out of the rocks, often using cyanide. A newly discovered process is being described as possibly displacing the cyanide.