Mecoprop-diolamine is produced through the same neutralisation-driven industrial logic used for other amine-salt forms of phenoxy herbicides. The process begins with manufacture and purification of racemic mecoprop acid via the standard phenoxypropionate route. The acid is then dissolved or slurried in water and reacted with diethanolamine (the “diolamine”) under controlled pH and temperature, ensuring complete salt formation while preventing esterification of the acid by the diolamine’s hydroxyl groups. Once neutralisation reaches the target stoichiometry, the resulting aqueous mecoprop diolamine solution is filtered to remove any insoluble residues, adjusted for active-ingredient concentration.