A new material, the water soluble blend of poly-vinylalcohol and collagen hydrolysate (PVA/CH) was developed in Slovakia. Results from a recent biodegradation study including three blend variants differing in the collagen content are presented. Two different biodegradation tests, one in compost environment, the other at aquatic conditions and additional compost analysis after degradation of the polymer have been done. Degradation rates were determined for both test systems and the carbon conversion rates were calculated by drawing up a carbon balance out of the aquatic test. The results proofed positive influence of collagen hydrolysate on degradation but also show a relatively low biological degradability of PVA under the applied test conditions. At least, no negative influence on the compost composition was detected. (C) 2004 Elsevier Ltd. All rights reserved.