Salt for water treatment: all you need to know about quality standards

EN, DIN and AFNOR

Most regulations regarding the use of salt come down to EN, DIN and AFNOR; norms which are issued by the European Standards Organisations, the Deutsches Institut für Normung and the French Association of Standardisation respectively.

Each standard is identified by a reference code which contains letters followed by a series of numbers. Standards in the salt industry predominantly concern purity, quality, grain size distribution, insolubilities and additives.

Quality standards for salt: the essentials

If you are not familiar with the standards that apply to salt, the combinations of letters and numbers can appear difficult to decipher – yet they reveal plenty of information:

• EN 973 Type A: This EU standard is the overarching European norm and is based on DIN and AFNOR. It applies to sodium chloride used for water softening, more specifically for the regeneration of ion exchangers which treat water intended for human consumption or food production. The standard indicates the requirements and corresponding test methods for sodium chloride. Softening salt that complies with EN 973 Type A has the highest purity level. Type B salt is less pure, i.e. it is not recommended for water softening.
   
• DIN19604: This German standard describes the technical requirements for sodium chloride used for water softening, more specifically for the regeneration of ion exchangers which treat water intended for human consumption or industrial use. The salt can be granular (the grain size depending on the application) or tablet-shaped. DIN19604 describes the salt’s characteristics and indicates the requirements and corresponding test methods.
   
• AFNOR T90-612: This French standard describes the characteristics of sodium chloride for water softening, with the purpose of manufacturing brine used for the regeneration of ion-exchanging resins for water treatment. The salt can be granular (the grain size depending on the application) or tablet-shaped. AFNOR T90-612 describes the salt’s characteristics and indicates the requirements and corresponding test methods. 
   
• EN16370: A European standard which applies to sodium chloride used for in situ electro-chlorination (disinfection) of water intended for human consumption, with the electro-chlorination involving membrane cells. The standard describes the salt’s characteristics and indicates the requirements and corresponding test methods. To name a few characteristics: the salt is additive-free and contains 99.9% NaCl.
   
• EN16401: A European standard which applies to sodium chloride used for electro-chlorinator systems. It does not apply to mixtures containing other chemicals used for swimming pool water treatment. The standard describes the characteristics of the sodium chloride and indicates the requirements and corresponding test methods. One specific requirement is that the salt does not contain any additives. EN16401 Type A salt has the highest purity level. Type B salt is less pure.
   
• BPR EU 528/2012 refers to European biocidal legislation relating to the trade in and use of biocides containing active substances which are used for protecting humans, animals, materials or objects against harmful organisms such as pests or bacteria. In Belgium, products adhering to this standard are also recognized as precursors for in situ generated active chlorine, and each have their own notification number. Salt used in biocide processes (disinfection) has recently been recognized as a biocide and must therefore be registered.

In conclusion, whenever you require salt for one of the applications mentioned above, be sure to opt for a type that adheres to all prevailing standards and laws. The relevant standards are always stated on the packaging. Please find an overview of the Soft-Sel products and the corresponding standards and laws below.