Quick drying high build bitu Black is based on special type of bitumens for long term protection of Zinc coated ductile pipes. This QD High Build bituminous coating is specially designed to satisfy the test criteria set out in BS 6920: Part 1:2014 specification-Suitability of non-metallic products for use in contact with water intended for human consumption with regard to their effect on the quality of the water. WRAS approved for small surface area contact with potable water only.