housing authority from federal income taxation and (B) either (1) that the other tenants occupying the project shall pay a rental not less than one-seventh of their annual income but in no event greater than the maximum rental which could be obtained for such unit in light of the rentals charged for comparable units within the same market area; or (2) that the project is located in a blighted open area, or any decadent area, or any substandard area. Any bonds, notes or other securities issued by any local housing authority, or any agency or instrumentality designated or approved by any such authority, pursuant to the provisions of this paragraph, shall not create or imply any obligation or indebtedness of any kind on the part of any local housing authority, the commonwealth, or any political subdivision thereof. The department may promulgate such rules and regulations as it may deem necessary to further the purposes of this paragraph.