EN 938:2016/prA1

Chemicals used for treatment of water intended for human consumption - Sodium chlorite

This European Standard is applicable to sodium chlorite used for treatment of water intended for human consumption. It describes the characteristics of sodium chlorite and specifies the requirements and the corresponding test methods for sodium chlorite. It gives information on its use in water treatment.

Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Natriumchlorit

No Scope Available.

Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation humaine - Chlorite de sodium

No Scope Available.

Kemikalije, ki se uporabljajo za pripravo pitne vode - Natrijev klorit

General Information

• Status: Not Published
• Publication Date: 09-Aug-2021
• ICS: 71.100.80 - Chemicals for purification of water
• Technical Committee: CEN/TC 164 - Water supply
• Drafting Committee: CEN/TC 164/WG 9 - Drinking water treatment
• Current Stage: 4098 - Decision to abandon - Enquiry
• Start Date: 25-Jun-2020
• Completion Date: 14-Apr-2025
• Ref Project: SIST EN 938:2016/oprA1:2019 - Chemicals used for treatment of water intended for human consumption - Sodium chlorite

Relations

• Amends: EN 938:2016 - Chemicals used for treatment of water intended for human consumption - Sodium chlorite
• Effective Date: 20-Feb-2019

Overview

EN 938:2016/prA1 is a CEN draft amendment to the European standard EN 938:2016 that applies to sodium chlorite used for treatment of water intended for human consumption. The standard describes the characteristics of sodium chlorite, specifies product requirements and corresponding test methods, and gives information on its use in drinking-water treatment. The A1 draft (July 2019) was prepared by CEN/TC 164 (Water Supply) and updates impurity limits and analytical procedures.

Key topics and technical requirements

• Scope and applicability: Covers sodium chlorite formulations intended for drinking-water treatment and control of quality relevant to human consumption.
• Impurity limits: The amendment replaces Table 5 to specify impurity limits. Notably, sodium chlorate (NaClO3) is limited to a maximum of 40 g/kg of sodium chlorite (per the 100% mass fraction specification). The standard notes that chlorate can be a manufacturing by‑product.
• Analytical methods: The draft modifies Clause 5.2.2.1.7 to define the laboratory procedure for chlorate quantification:
  • Calibration using five concentration levels and determination of the regression line.
  • Calculation of chlorate concentration in the test solution (mg/L) from the calibration result, sample dilution volume and sample mass.
  • Conversion of measured chlorate (mg/L) to sodium chlorate content expressed in g/kg of sodium chlorite, accounting for solution density and the sodium chlorite mass fraction; a conversion factor (1.275) is included in the formula.
• Documentation and compliance: The draft amendment is circulated for CEN enquiry and, if approved, is to be integrated into national standards per CEN/CENELEC regulations.

Applications and users

This standard is directly relevant for:

• Water utilities and municipal treatment plants specifying and accepting sodium chlorite for potable water treatment.
• Chemical manufacturers and suppliers who produce, label and certify sodium chlorite formulations for drinking-water applications.
• Analytical laboratories performing quality control and regulatory compliance testing (chlorate determination, impurity profiling).
• Regulators, procurement officers and consultants developing specifications, risk assessments and compliance criteria for drinking-water chemicals.

Practical uses include product specification, supplier qualification, routine quality control, and ensuring compliance with impurity limits to protect public health.

Related standards and context

• EN 938:2016 is the base European standard on chemicals for treatment of drinking water; prA1 is its proposed amendment.
• The document was prepared by CEN/TC 164 (Water Supply) and is intended to be adopted by CEN member bodies across Europe. For full compliance and implementation, consult the current official EN 938 text and national transpositions.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2019
Kemikalije, ki se uporabljajo za pripravo pitne vode - Natrijev klorit
Chemicals used for treatment of water intended for human consumption - Sodium
chlorite
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Natriumchlorit
Produits chimiques utilisés pour le traitement de l'eau destinée à la consommation
humaine - Chlorite de sodium
Ta slovenski standard je istoveten z: EN 938:2016/prA1
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 Kemikalije za čiščenje vode Chemicals for purification of
water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
EN 938:2016
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
July 2019
ICS 71.100.80
English Version
Chemicals used for treatment of water intended for human
consumption - Sodium chlorite
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Chlorite de menschlichen Gebrauch - Natriumchlorit
sodium
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 164.

This draft amendment A1, if approved, will modify the European Standard EN 938:2016. If this draft becomes an amendment,
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of
this amendment into the relevant national standard without any alteration.

This draft amendment was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice
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