The protein family of small GTPases controls cellular processes by acting as a binary switch between an active and an inactive state. The most prominent family members are H Ras, N Ras, and K Ras isoforms, which are highly related and frequently mutated in cancer. Bisphenols are widespread in modern life because of their industrial application as plasticisers. Bisphenol A (BPA) is the best known member and has gained significant scientific as well as public attention as an endocrine disrupting chemical, a fact that eventually led to its replacement. However, compounds used to replace BPA still contain the molecular scaffold of bisphenols. BPA, BPAF, BPB, BPE, BPF and an amine substituted BPAF derivate all interact with all GDP-bound Ras Isoforms through binding to a common site on these proteins. NMR-, SOScat-, and GDI- assay based data revealed a new Bisphenol-induced, allosterically activated GDP bound Ras conformation that define these plasticisers as Ras allosteric agonists.