Government Procurement Act Article 96

An entity may provide in the tender documentation that preference shall be given to a product which has been permitted to use a label of environment protection approved by the government, and in addition has the same or similar functions. The said preference may include a price preference of not exceeding ten percent. Such preference shall also be given where a product or its raw material is manufactured, used, and disposed of in such manner that conform to recycled materials, returnable products, low pollution, or energy-saving requirements.The preceding paragraph shall apply mutatis mutandis to other products which either increase social benefits or reduce social costs, and have the same or similar functions required.The categories and coverage of products referred to in the two preceding paragraphs and the implementing regulations thereof shall be jointly prescribed by the responsible entity, the Environmental Protection Administration of the Executive Yuan, and other competent entities.
中文原文 政府採購法第96條
機關得於招標文件中,規定優先採購取得政府認可之環境保護標章使用許可,而其效能相同或相似之產品,並得允許百分之十以下之價差。
產品或其原料之製造、使用過程及廢棄物處理,符合再生材質、可回收、低污染或省能源者,亦同。
其他增加社會利益或減少社會成本,而效能相同或相似之產品,準用前項之規定。
前二項產品之種類、範圍及實施辦法,由主管機關會同行政院環境保護署及相關目的事業主管機關定之。

English translation for reference only; the Chinese text prevails. Not legal advice.