Un plastique biodégradable?

The quest for impermanence

In the mid-1990s, a certain mail-order computer retailer
announced that it was abandoning Styrofoam (polystyrene) packing
peanuts in its shipments and switching to environmentally friendly
cornstarch peanuts instead. The new filler material, they explained,
was not merely biodegradable, it would dissolve almost instantly in
water.