On the slow march towards 90%
I'm a controversial chemical compound. I was used in early rocket fuels, and I'm still found in some transport fuels even though my emissions affect ozone levels. I'm effective at killing small organisms and I'm commonly sold for this purpose. If ingested, I cause psychoactive effects. My common name is derived from Arabic. What is it?
I'm one of Plato's Five. To him, I looked like the heavens. But nowadays you're more likely to come across me as a hipster cactus or candle holder.