Zirconium Butoxide, ZB, 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 tetrabutanolate, ZB, CAS# 1071-76-7. Our REACH registration number is 01-2120769499-31-0001 and product is available from stock.