Under contemporary neoliberalism, standards and certification have become the leading governance mechanism for determining what sustainability entails, how to measure it, and how to assess it. However, this governance mechanism is increasingly critiqued due to its knowledge production, reliance on quantitative indicators, and lack of democratic accountability. By using recent theories of valuation and standards, this paper explores the valuation processes used in alternative approaches to defining, measuring, and assessing sustainability. In doing so, this paper argues that participatory guarantee systems offer an alternative approach to sustainability governance, one that may be more democratic and hence, produce forms of sustainability that incorporate the lived experiences of people around the world.