Eight House Democrats and 48 House Republicans sent a letter to the General Services Administration May 18 saying that proposed changes to a third-party rating system to certify green buildings place arbitrary restrictions on chemicals used in building products and could drive up building costs. The newest version of the Leadership in Energy and Environmental Design rating system would eliminate the use of dozens of materials and hundreds of building products. The group asked GSA Acting Administrator Daniel Tangherlini to drop the newest version unless the U.S. Green Building Council revises the proposed standards. The latest version of the LEED system is out for public comment, with a final version expected in November.