MEK occurs in nature. It’s found in some trees, as well as small amounts in fruits and vegetables that humans eat, so humans have had MEK in their diet for thousands of years. It relatively safe in small amounts. I don’t know about the other stuff.

The solvents that humans have had in their diets for thousands of years include alcohol, acetone, d-limonene, MEK, and I’m sure a few others as well. All of these are safe to ingest in very small amounts because the human digestive system has evolved to cope with these solvents. They are present in small amounts in all sorts of foods we eat on a daily bases.