Overview
EN 12931:2015 (CEN) specifies requirements for sodium dichloroisocyanurate, anhydrous (NaDCC) when used for emergency treatment of water intended for human consumption. The standard defines the product identity, physical and chemical characteristics, purity criteria and corresponding test methods, and provides guidance on safe handling, labelling, transportation and storage (notably Annex A - use information, and Annex B - safety rules). EN 12931:2015 supersedes the 2008 edition and is intended for use across CEN member states.
Key topics and technical requirements
- Scope & identification: Chemical name, synonyms (e.g., troclosene sodium), CAS number 2893-78-9, empirical formula C3N3O3Cl2Na and relative molecular mass 219.98.
- Physical properties: white granular solid with chlorinous odour; bulk density ~0.9 g/cm3; solubility ~250 g/L at 25 °C; specific heat ~1.09 ± 0.04 kJ/kg·K.
- Purity and composition: requirements for the composition of the commercial product and limits on impurities and by‑products (detailed testable criteria are given in the standard).
- Test methods: procedures for sampling, determination of available chlorine, analysis of impurities and chemical parameters. Annex C describes atomic absorption hydride techniques for determination of arsenic, antimony and selenium.
- Labelling & regulatory alignment: labelling and safety information updated to current EU chemical regulation; transportation and marking requirements are specified.
- Safety & emergency procedures: Annex B covers safe handling, first aid, spill response and fire measures, plus storage incompatibilities and long‑term stability guidance.
Applications and who uses it
EN 12931:2015 is targeted at organizations involved in emergency water treatment and public health protection:
- Water utilities and emergency responders needing validated products and dosing guidance for emergency disinfection of drinking water.
- Chemical manufacturers and suppliers producing, packing and labelling sodium dichloroisocyanurate (anhydrous) to meet European quality and safety requirements.
- Testing laboratories performing acceptance and compliance testing (available chlorine, impurity analysis, AAS methods).
- Regulators and procurement officers specifying compliant emergency water treatment chemicals and safety documentation.
Practical benefits include consistent product quality, verified test methods for acceptance testing, and clear safety/transport instructions for use in disaster relief and contingency planning.
Related standards
Normative references in EN 12931:2015 include:
For compliance or procurement, consult the full EN 12931:2015 document from your national standards body.