Discloses a method for the manufacture of an oil-in-water emulsion, comprising: (i) preparing squalene from a composition comprising squalene from an animal source by a process comprising steps of: (a) a purification distillation carried out at a temperature T1； and (b) a denaturing distillation carried out at a temperature T2； wherein steps (a) and (b) may be performed in either order； T1 and T2 are sufficient to cause squalene to boil； T2 is greater than T1； and T2 is greater than or equal to 200°C； and (ii) preparing an oil-in-water emulsion using the squalene prepared in step (i).
