Municipal solid waste (MSW), presently a major disposal problem, represents a significant source of metals and glass together with a combustible fraction that could be used to supplement coal and oil and in generating heat and electricity. This combustible fraction represents 70 weight-percent MSW; therefore, effective utility of this fraction is an essential part of the Bureau of Mines program to conserve and increase the nation's mineral and fuel supply through recycling of urban waste. Because of the increasing national interest in this important fuel supplement, the U.S. Department of the interior, Bureau of Mines prepared a refuse-derived fuel material as a proposed reference material for use by other laboratories to evaluate their analytical procedures. This reference material was prepared by combining MSW light combustibles from Tampa, Florida, Montgomery County, Maryland, and Tulsa, Oklahoma, then shredding, milling, and blending the composite material. Homogeneity of the refuse-derived fuel reference material (rdfrm) appears to be acceptable based on analytical values for replicate analyses. Concentration data for major, minor, and trace elements together with proximate analyses are provided in this report. Aliquots of the rdfrm are available to interested laboratories upon request.