Life Cycle Assessment(LCA) is crucial for evaluating the ecological sustainability of a product or service, and the accurate evaluation of sustainability requires detailed and transparent information about industrial activities. However, such information is usually considered confidential and withheld from the public. In this paper, we present a rigorous study of privacy in the context of LCA. The main goal is to explore the privacy challenges in sustainability assessment considering the protection of trade secrets while increasing transparency of industrial activities. To overcome privacy concerns, we apply differential privacy to LCA computations considering the idiosyncratic features of LCA data. Our assessments on a specific real-life example show that it is possible to achieve privacy-preserving LCA computations without losing the utility of data completely.