In the treatment of acetaminophen overdose, acetylcysteine acts to maintain or replenish depleted glutathione reserves in the liver and enhance non-toxic metabolism of acetaminophen.
The design called for a different, non-toxic chemical, but this had been substituted with an alternative chemical, which had approximately the same functional properties.
Biodiesel (in its pure form) is a non-toxic, biodegradable form of diesel fuel made from vegetable oil, usually soybean oil or recycled restaurant grease.