The adoption of food standards to regulate product characteristics or its processing methods is widely widespread. Food economics literature has intensively explored the firm incentives for the adoption of safety and quality standards. A growing body of literature discusses on voluntary standards as alternative forms of governance of vertical relationships due to the increase of information transparency provided. There is a gap in the understanding of the determinants leading food firms to choose such alternative forms of transaction governance. The present study aims at exploring the significant drivers of voluntary standard adoption. To answer the questions we start from Transaction Cost Economic theory and we refer to an extended conceptual framework based on transaction risks, namely, risks arising from the opportunistic behaviour of economic agents (internal risks) and other risks related to unexpected changes in the economic environment (exogenous risks). Data was collected through interviews on an EU representative survey concerning the non-GMO voluntary standard in the soybean supply chain. The survey includes 363 companies from 15 EU countries. Preliminary results of the logit model suggest a positive relationship of transaction internal risks with the adoption of the voluntary non-GMO standard and a negative relationship of exogenous risks with the implementation of the standard. Acknowledgement :