Tax exemption for welfare board: specified cess and interest incomes exempt subject to non commercial, unchanged activity and filing conditions. Central Government notifies that the Chandigarh Building and Other Construction Workers Welfare Board's specified income - proceeds of the cess under the Building & Other Construction Workers Welfare Cess Act and interest income from investment - is exempt under clause (46) of section 10 of the Income tax Act for financial years 2015-16 to 2019-20, subject to conditions that the board not engage in commercial activity, that activities and the nature of specified income remain unchanged during the year, and that the board files its return of income as required.