According to Gunter's space[1] they use kerosene and liquid oxygen (LOX) as propellant and oxidizer. According to this 2004 ESA study[2] "the most promising green propellant combinations considering toxicity, launcher aspects, storability, technology seems to be LOX-kerosene and LOX-propane". I don't know about the environmental impact of debris from a failed launch though.

[1] https://space.skyrocket.de/doc_lau/astra.htm [2] http://articles.adsabs.harvard.edu//full/2004ESASP.557E...4H...