Perlite is made by mining a volcanic obsidian type rock, crushing it, superheating it, and it pops like popcorn into like 15X it's original size. So it's a 100% organic material. Sometimes you willl see a slight Nutrient NPK analysis on a bag like 0.04-0.01-0.06.
Typical elemental Chemical analysis is all things a plant can use, (like oxygen or air !) doubt if styro allows exchange of air into the pellets or your coffee cup would leak.
Silicone: 33.8 %
Aluminum: 7.2
Potassium: 3.5
Sodium: 3.4
Iron: 0.6
Calcium: 0.6
Magnesium: 0.2
Traces: 0.2
Oxygen 47.5
Bound Water 3.0
Total % 100.0
Styrofoam is made from petroleum, and invented by Dow Chemical. I don't think my plants need petrochemicals, but you may be on to something.
Perlite is dirt cheap.
Nuff said ?
