PROBLEM TO BE SOLVED: To provide a recycled pulp fiber with less protein-containing component which can be eluted into water and capable of being used in occasions to be in contact with waters, and derived from used sanitation supplies.SOLUTION: The invention relates to a recycled pulp fiber derived from a used sanitation supplies, wherein the recycled pulp fiber is characterized by that an aqueous dispersion containing the recycled pulp fiber dispersed with a solid content concentration of 5.0 mass% contains a protein at a concentration of 60 μg/mL or under, measured by Modified Lowry method.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2020,JPO&INPIT【課題】水中に溶出しうるタンパク質含有成分が少なく、水分と接触する用途に用いることができる、使用済の衛生用品に由来するリサイクルパルプ繊維を提供すること。【解決手段】使用済の衛生用品に由来するリサイクルパルプ繊維であって、上記リサイクルパルプ繊維を５．０質量％の固形分濃度で分散させた水分散液が、タンパク質を、Ｍｏｄｉｆｉｅｄ Ｌｏｗｒｙ法により測定された６０μｇ／ｍＬ以下の濃度で含むリサイクルパルプ繊維。【選択図】図２
