A method for increasing the BEMT content in a composition comprising 2,4-bis[4-(2-ethylhexyloxy)-2-hydroxyphenol]-6-(4-methoxyphenol)-1,3,5-
triazine (BEMT), the method comprising the steps of: a) providing a composition comprising BEMT and impurities; b) dissolving the composition in a
solvent mixture at a first
dissolution temperature to produce an unsaturated BEMT solution, wherein the
solvent mixture comprises at least one polar
solvent; c) lowering the temperature of the unsaturated BEMT solution to a saturation temperature, wherein the saturation temperature is below the first
dissolution temperature, to produce a saturated BEMT solution; d) further lowering the temperature of the first saturated BEMT solution to a first
crystallization temperature, wherein the first
crystallization temperature is below the saturation temperature, thereby producing a supersaturated BEMT solution; e) during step d), adding BEMT seed crystals in an amount
ranging from 0.00001 wt.-% to 20 wt.-% relative to the total weight of the composition to the supersaturated BEMT solution to produce a first BEMT suspension comprising BEMT particles; f) a) Heating the first BEMT suspension to a second
dissolution temperature to produce a second BEMT suspension containing fewer BEMT particles than the first BEMT suspension, wherein the second dissolution temperature is higher than and lower than the first
crystallization temperature; g) Cooling the second BEMT suspension to a second
crystallization temperature to produce a final BEMT suspension containing BEMT particles larger than those in the first BEMT suspension; h) Separating these BEMT particles from the final BEMT suspension, wherein the second
crystallization temperature is lower than the first
crystallization temperature.