Zirconium Propoxide, NPZ REACH Posted on 13th December 2018 by admin CTL can confirm that we have now completed full REACH registration in the 1-100 MT per annum tier for zirconium tetrapropanolate, NPZ, CAS# 23519-77-9. Our REACH registration number is 01-2120769493-43-0001 and product is available from stock.