1. The activities of nationally affiliated fraternal, benevolent, or service organizations which promote good citizenship, humanitarian activities, or improve the physical, mental, and moral condition of an indefinite number of people are purposes purely charitable within the meaning of Subsection 1 of Section 6 of Article X of the Constitution and local assessing authorities may exempt such portion of the real and personal property of such organizations as the assessing authority may determine is utilized in purposes purely charitable from the assessment, levy, and collection of taxes.

2. If, at any time, an assessor finally determines, after any and all hearings or rightful appeals, that personal property, upon which an organization would otherwise owe taxes but for the provisions of subsection 1 of this section or subdivision (5) of section 137.100, is not used for purposes purely charitable, or for purposes described in subdivision (5) of section 137.100, then the assessor shall notify the department of revenue of such final determination within thirty days.