This European Standard is applicable to iron based coagulants (iron (III) chloride, iron (III) chloride sulfate and iron (III) sulfate liquid) used directly or for the production of formulations for treatment of water for swimming pools. It describes the characteristics of iron based coagulants and specifies the requirements and the corresponding test methods for iron based coagulants. It gives information on their use in swimming pool water treatment. General information on iron based coagulants is given in Annex A. It also determines the rules relating to safe handling and use (see Annex B).