Ever since the Stone Age, humans have preferred natural products and materials for better health and comfortability. Wool and natural silk have been used in the textile clothing thousands of years ago. The performance and appearance attributes of wool and silk make them superior for many applications. On the other hand, the textile industries are technically, economically, socially, and environmentally related to some of the sustainable development goals (SDGs) of the United Nations Agenda 2030. For instance, the item number 12 in the SDGs aims to ensure sustainable consumption and production pattern. This necessitates proper utilization of all natural products as well as recycling and utilization of any waste thereof.
This article review deals with retrieval of wastes or by-products during wet processing of proteinic fibres; namely wool and silk. Different ways of proper utilization of the retrieved materials will be proposed. Specifically, we will focus mainly on three main by-products; namely keratinous materials, wool wax, and sericin. State of the art and future prospects for the utilization of these materials in the production of textile auxiliaries; Viz. softeners, binders, and flame-retardants, were discussed.