Road asphalt, traditionally produced at high temperature with bitumen, can be made cold using bitumen emulsions, reducing CO₂ emissions by 50%. To take decarbonization a step further, biobased binders can partially or totally replace bitumen. Such as modified waste cooking oils (WCO). This preliminary study investigates the influence of oils and surfactants on emulsification and emulsion stability. For this, 6 oils were studied (WCO, olive, sunflower, linseed, palm, canola), with three types of surfactant (cationic, anionic, non-ionic). The interfacial tension and particle size distribution of the emulsions were used to qualify this influence. The results show that the acid number influences the oil/water interfacial tension, which decreases with increasing free fatty acids until saturation (~10 mN/m) is reached. In addition, a surfactant concentration greater than twice the CMC significantly improves emulsion stability. The study then looked at the influence of the nature of the surfactant and its concentration on the emulsification and stability of emulsions. It would appear that charged surfactants enable droplets of around 5µm to be formed, while the effectiveness of the uncharged surfactant seems to depend on its concentration. Stability remains assured overall, except at low doses (0.5 cmc), where phase separation occurs.