Abstract: A process for separating a formaldehyde-containing product from a formalin solution comprising formaldehyde, water and methanol, wherein said formaldehyde-containing product contains substantially less water than said formalin solution, comprising distilling said formalin solution in the presence of a water entraining compound, especially methyl propionate or methyl methacrylate. The formaldehyde-containing product is suitable for use in a further process which requires a source of formaldehyde containing a relatively low level of water. One example of such a process is the reaction of methyl propionate with formaldehyde and methanol over a catalyst to produce methyl methacrylate.