Today’s society relies significantly on the use of plastics of all kinds. While the material provides many benefits, plastic pollution poses a heavy threat to the environment. To reduce the environmental impact of plastics while still benefitting from their use, various certifications aim at labelling different plastic products as sustainable. To ensure that those certifications really label plastics that contribute to sustainable development, it is important to analyse which labels are scientifically sound and useful instruments to enhance environmental standards, and which might contribute to greenwashing. However, a certification can only be as good as the practical implication it has. The example of Berdal Rubber & Plastics BV, a Dutch producer of plastic buckets and tubs, shows that a key challenge arises from communicating the importance of adopting such certifications to business customers, in their case, especially in the building and DIY industry. Hence, this research tackled the following research question: How can the scientific soundness of sustainable plastics certifications in the European building and DIY industry be assessed and how can the importance of using such certifications be successfully communicated to the buyers and end-users of plastic products? To answer this research question, inductive research making use of a mixed-methods approach has been conducted, in which Berdal served as a case study. As a first step, this research developed an analysis framework for certifications, then, it researched what a successful communication strategy for certifications that includes said framework can look like. A major challenge that has been identified is to change the sometimes still unfavourable attitudes towards certifications and sustainability found within the building and DIY industries. Additionally, the low understandability of certifications limits their use, while being difficult to target by communication strategies. However, communication on certifications and sustainability can be more successful when it considers certain aspects. Especially the dialogue with stakeholders and credibility through proactiveness are seen to be important. Target group specific communication that focusses on personal relevance is found to be another aspect to consider. Here, the role of the framework can be to present information in a clear and detailed way, and to be an instrument to point out the advantages a specific certification can have for the communication’s receiver. For the specific situation of the case study of Berdal, it has been found that setting up a reciprocal dialogue, especially with their buyers, and emphasising the credibility of their message about certifications by focussing on their reliability and standard setting can be beneficial. Additionally, the focus of communication should lie on the personal benefits of their stakeholders individually. The framework for Berdal as a plastics producer can be used to transparently show why certain certifications have been chosen or how they compare to others.