SIST EN 935:2005

• Abstract:

  This document is applicable to aluminium iron (III) chloride (monomeric) and aluminium iron (III) chloride hydroxide (monomeric) used for treatment of water intended for human consumption. It describes the characteristics and specifies the requirements for aluminium iron (III) chloride (monomeric) and aluminium iron (III) chloride hydroxide (monomeric) and refers to the corresponding test methods. It gives information on their use in water treatment. It also determines the rules relating to safe handling and use of aluminium iron (III) chloride (monomeric) and aluminium iron (III) chloride hydroxide (monomeric) ( see annex B).

• Status: Published
• Publication Date: 28-Feb-2005
• ICS: 13.060.20 - Drinking water
• ICS: 71.100.80 - Chemicals for purification of water
• Technical Committee: IOVO - Water supply and waste water engineering
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Mar-2005
• Due Date: 01-Mar-2005
• Completion Date: 01-Mar-2005
• Directive: 93/38/EEC - Procurement procedures of entities operating in the water, energy, transport and telecommunications sectors
• Mandate: M/BC/CEN/88/15 - Standardization request to CEN/CENELEC in the field of Water supply, drainage and sewerage
• Ref Project: EN 935:2004 - Chemicals used for treatment of water intended for human consumption - Aluminium iron(III) chloride (monomeric) and aluminium iron(III) chloride hydroxide (monomeric)

• Replaces: SIST EN 935:2002 - Chemicals used for treatment of water intended for human consumption - Aluminium iron(III) chloride (monomeric) and aluminium iron(III) chloride hydroxide (monomeric)
• Effective Date: 01-Mar-2005
• Refers: SIST ISO 6206:1995 - Chemical products for industrial use -- Sampling -- Vocabulary
• Effective Date: 25-Aug-2026
• Refers: SIST ISO 3165:1995 - Sampling of chemical products for industrial use -- Safety in sampling
• Effective Date: 25-Aug-2026
• Refers: SIST EN 1302:2025 - Chemicals used for treatment of water intended for human consumption - Aluminium-based coagulants - Analytical methods
• Effective Date: 28-Jan-2026
• Refers: SIST EN 1998-6:2005 - Eurocode 8: Design of structures for earthquake resistance - Part 6: Towers, masts and chimneys
• Effective Date: 28-Jan-2026
• Refers: SIST EN ISO 8751:2001 - Spring-type straight pins - Coiled, light duty (ISO 8751:1997)
• Effective Date: 28-Jan-2026
• Referred By: SIST EN ISO 13628-4:2011 - Petroleum and natural gas industries - Design and operation of subsea production systems - Part 4: Subsea wellhead and tree equipment (ISO 13628-4:2010)
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 1302:2000 - Chemicals used for treatment of water intended for human consumption - Aluminium-based coagulants - Analytical methods
• Effective Date: 28-Jan-2026
• Referred By: SIST EN ISO 13624-1:2010 - Petroleum and natural gas industries - Drilling and production equipment - Part 1: Design and operation of marine drilling riser equipment (ISO 13624-1:2009)
• Effective Date: 28-Jan-2026

SIST EN 935:2005 is a Slovenian standard from SIST for aluminium iron(III) chloride (monomeric) and aluminium iron(III) chloride hydroxide (monomeric) used in treatment of water intended for human consumption. It specifies the product characteristics, purity criteria, test methods, marking, transport, storage, and safety rules for people who supply, test, or use these chemicals.

What does SIST EN 935:2005 specify?

SIST EN 935:2005 applies to two liquid coagulants used in drinking-water treatment: aluminium iron(III) chloride (monomeric) and aluminium iron(III) chloride hydroxide (monomeric). The standard gives the structure of the document, with clauses on scope, references, description, purity, test methods, and labelling-transport-storage, plus informative and normative annexes.

Annex	What it covers
Annex A	General information on the products, including origin, manufacture, use, dose, application, and effects on treated water
Annex B	General rules relating to safety, including first aid, spill response, and fire advice

What are the key requirements of SIST EN 935:2005?

SIST EN 935:2005 sets limits for composition and impurities, defines how samples are taken and analysed, and requires specific marking, transport, storage, and safety practices. In practice, these are the points a buyer, plant operator, or lab uses to accept a delivery and use the product correctly.

Composition and product form

SIST EN 935:2005 says the products are available as liquids and are yellow to brown in appearance. They are fully miscible with water, but dilution can cause hydrolysis and precipitation, so dosing conditions matter in treatment plant operation.

For composition, the standard requires the aluminium ion content to be above a minimum level, and the declared aluminium and iron contents to stay within a close tolerance of the manufacturer’s values. It also limits the Fe/Al ratio and the relative basicity for the hydroxide product, which means users need to check the declared grade and not just the product name.

Purity and trace metals

SIST EN 935:2005 limits insoluble matter and sets maximum levels for trace metals in Table 1. The table covers arsenic, cadmium, chromium, mercury, nickel, lead, antimony, and selenium for three product Types.

That matters because these impurities can end up in treated water or sludge. Annex A.2 explains that the three Types reflect commercially available quality levels, so users should select the grade that matches their raw water, dosage, and treated-water targets.

Sampling and analysis

SIST EN 935:2005 requires sampling to follow ISO 3165 and ISO 6206, and the analytical work to use EN 1302. Clause 5 also gives practical sampling methods for drums, bottles, tanks, and tankers.

This is important because liquid coagulants can stratify or have surface contamination. The document therefore tells the sampler when to mix, when to take surface samples, and when to take bottom samples so the test result represents the whole delivery.

Marking, transport, storage, and safety

SIST EN 935:2005 requires delivery in corrosion-resistant tankers suitable for the product, and storage in corrosion-resistant tanks. It also sets marking items such as product name, net mass, supplier details, and the statement that the product conforms to EN 935.

The standard links the product to either irritant or corrosive risk labelling, depending on composition and concentration, and notes transport classification as UN 1760 with class 8 transport provisions where applicable. Annex B gives the safety response: wash skin or eyes with plenty of water, do not induce vomiting after ingestion, control spills carefully, and treat the products as non-flammable liquids.

What terms does SIST EN 935:2005 define?

• Aluminium iron(III) chloride (monomeric) - A liquid coagulant based on aluminium and iron chlorides used for water treatment.
• Aluminium iron(III) chloride hydroxide (monomeric) - A basified liquid coagulant with aluminium, iron, chloride, and hydroxide used in the same application.
• Relative basicity - The mole ratio OH/3(Al + Fe), used to distinguish and control the hydroxide product.
• Active matter - The aluminium ion content expressed as grams per kilogram of product, used as a strength indicator.
• CAS Registry Number - A chemical identifier listed for the product components and compounds.
• EINECS reference - The European inventory number used to identify the listed substances or components.
• Fe/Al - The iron-to-aluminium ratio, which helps define product composition and grade.

Who uses SIST EN 935:2005?

SIST EN 935:2005 is used by drinking-water treatment operators, chemical suppliers, laboratory staff, and quality or procurement teams. They use it to choose the right product grade, verify deliveries, sample and test batches, label and store the chemical correctly, and apply it safely in water treatment.

What changed in SIST EN 935:2005 from the previous edition?

SIST EN 935:2005 supersedes EN 935:2001 and replaces SIST EN 935:2002. The foreword lists two technical changes: the reference to EU Directive 80/778/EEC was replaced by the latest directive in force, and Annex A was expanded with A.2, which covers the quality of the commercial product.

Which standards are used with SIST EN 935:2005?

• EN 1302 - Provides the analytical methods used to test the products.
• ISO 3165 - Gives the general rules for sampling chemical products for industrial use.
• ISO 6206 - Provides the vocabulary for sampling chemical products for industrial use.

What does the SIST EN 935:2005 document contain?

SIST EN 935:2005 contains a product description, purity criteria, test methods, and instructions for labelling, transportation, and storage. Clause 5 gives detailed sampling procedures for containers and bulk deliveries, while Table 1 sets the chemical parameter limits for the product Types.

Annex A gives background on raw materials, manufacturing routes, treatment use, dosage, application method, and secondary effects such as lower pH and higher chloride. It also includes Figures A.1 to A.3 showing the expected maximum impact of the three product Types on trace metal content in treated water.

Annex B provides practical safety guidance for handling, spills, first aid, and fire response.

SLOVENSKI STANDARD
01-marec-2005
1DGRPHãþD
SIST EN 935:2002
Kemikalije, ki se uporabljajo za pripravo pitne vode – Aluminijev železov (III) klorid
(monomerni) in aluminijev železov (III) klorid hidroksid (monomerni)
Chemicals used for treatment of water intended for human consumption - Aluminium iron
(III) chloride (monomeric) and aluminium iron(III) chloride hydroxide (monomeric)
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Aluminium-
Eisen(III)chlorid (Monomer) und Aluminium-Eisen(III)hydroxidchlorid (Monomer)
Produits chimiques utilisés pour le traitement de l'eau destinée a la consommation
humaine - Chlorure et hydroxychlorure d'aluminium et de fer (III) (monomeres)
Ta slovenski standard je istoveten z: EN 935:2004
ICS:
13.060.20 Pitna voda Drinking water
71.100.80 .HPLNDOLMH]DþLãþHQMHYRGH Chemicals for purification of
water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 935
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2004
ICS 71.100.80 Supersedes EN 935:2001
English version
Chemicals used for treatment of water intended for human
consumption - Aluminium iron(III) chloride (monomeric) and
aluminium iron(III) chloride hydroxide (monomeric)
Produits chimiques utilisés pour le traitement de l'eau Produkte zur Aufbereitung von Wasser für den
destinée à la consommation humaine - Chlorure et menschlichen Gebrauch - Aluminium-Eisen(III)chlorid
hydroxychlorure d'aluminium et de fer (III) (monomères) (Monomer) und Aluminium-Eisen(III)hydroxidchlorid
(Monomer)
This European Standard was approved by CEN on 30 September 2004.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 935:2004: E
worldwide for CEN national Members.

Contents
Page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Description .5
4 Purity criteria.8
5 Test methods.9
6 Labelling - Transportation - Storage.10
Annex A (informative) General information on aluminium iron (lll) chloride (monomeric) and
aluminium iron (lll) chloride hydroxide (monomeric) .13
Annex B (normative) General rules relating to safety.17
Bibliography .18

Foreword
This document (EN 935:2004) has been prepared by Technical Committee CEN/TC 164 “Water supply”, the
secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical text or
by endorsement, at the latest by May 2005, and conflicting national standards shall be withdrawn at the latest by
May 2005.
This document supersedes EN 935:2001.
Significant technical differences between this edition and EN 935:2001 are as follows:
a) replacement of the reference to EU Directive 80/778/EEC of July, 15 1980 with the latest Directive in force
(see[1]);
b) expansion of annex A by addition of A.2 "quality of commercial product".
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused by the
product covered by this document:
a) this document provides no information as to whether the product may be used without restriction in any of the
Member States of the EU or EFTA;
b) it should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations
concerning the use and/or the characteristics of this product remain in force.
NOTE Conformity with this standard does not confer or imply acceptance or approval of the product in any of the Member
States of the EU or EFTA. The use of the product covered by this document is subject to regulation or control by National
Authorities.
1 Scope
This document is applicable to aluminium iron (III) chloride (monomeric) and aluminium iron (III) chloride hydroxide
(monomeric) used for treatment of water intended for human consumption. It describes the characteristics and
specifies the requirements for aluminium iron (III) chloride (monomeric) and aluminium iron (III) chloride hydroxide
(monomeric) and refers to the corresponding test methods. It gives information on their use in water treatment. It
also determines the rules relating to safe handling and use of aluminium iron (III) chloride (monomeric) and
aluminium iron (III) chloride hydroxide (monomeric) ( see annex B).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references,
only the edition cited applies. For undated references, the latest edition of the referenced document (including any
amendments) applies.
EN 1302, Chemicals used for treatment of water intended for human consumption — Aluminium-based
coagulants — Analytical methods.
ISO 3165, Sampling of chemical products for industrial use — Safety in sampling.
ISO 6206, Chemical products for industrial use — Sampling — Vocabulary.
3 Description
3.1 Identification
3.1.1 Chemical name
a) Aluminium iron (III) chloride (monomeric);
b) Aluminium iron (III) chloride hydroxide (monomeric).
3.1.2 Synonym or common names
For aluminium iron (III) chloride hydroxide (monomeric): bauxite or clay hydroxide chloride.
3.1.3 Relative molecular mass
Variable (see 3.1.4).
3.1.4 Empirical formula
Al Fe (OH) Cl with (a + b) = 3 and x = 0,67 to 0,99 for aluminium iron chlorides
x 1-x a b
x = 0,80 to 0,99 for aluminium iron chloride hydroxides
a = 0 to 1,05
b = 3 to 1,95
a = 0 for aluminium iron(III) chloride (monomeric) products, and these products normally have a detectable free
acidity (see 5.2).
3.1.5 Chemical formula
Variable (see 3.1.4).
1)
3.1.6 CAS Registry Number
The following is a list of CAS Registry Numbers for products or their components.
AlCl : 7446-70-0.
FeCl : 7705-08-0.
Al(OH) Cl : 1327-41-9 with (a + b) = 3 and a less than 1,05.
a b
Al(OH)Cl : 14215-15-7.
2)
3.1.7 EINECS reference
The following is a list of EINECS reference numbers for products or their components.
AlCl : 231-208-1.
FeCl : 231-729-4.
Al(OH) Cl : 215-477-2.
a b
Al(OH)Cl : 238-071-7.
3.2 Commercial form
The products are available as liquids.
3.3 Physical properties
3.3.1 Appearance
The products are yellow to brown liquids.

1) Chemical Abstracts Service Registry Number.
2) European inventory of Existing Commercial chemical Substances.
3.3.2 Density
The density depends on the particular composition, especially the aluminium ion content, expressed as a mass
fraction of aluminium in %.
Typical value: 1,3 g/ml for 5,3 % Al.
3.3.3 Solubility in water
Aluminium iron (III) chloride (monomeric) and aluminium iron (III) chloride hydroxide (monomeric) are fully miscible
with water.
NOTE Depending on the particular product, dilute solutions can hydrolyze and form a precipitate.
3.3.4 Vapour pressure at 20 °C
Not known.
3)
3.3.5 Boiling point at 100 kPa
Not known.
3.3.6 Crystallization point
Typical value is - 20 °C for 5,3 % Al.
3.3.7 Specific heat
Not known.
3.3.8 Viscosity (dynamic)
Typical value is 20 mPa·s for 5,3 % Al at 20 °C.
3.3.9 Critical temperature
Not applicable.
3.3.10 Critical pressure
Not applicable.
3.3.11 Physical hardness
Not applicable.
3) 100 kPa = 1 bar.
3.4 Chemical properties
Aluminium iron (III) chloride (monomeric) and aluminium iron (III) chloride hydroxide (monomeric) are acidic liquids
which hydrolyse and form a precipitate of aluminium hydroxide and iron hydroxide when diluted beyond a particular
concentration.
NOTE The solubility of aluminium and the solubility of iron depend on the pH value and the product should be used within
an appropriate pH range.
4 Purity criteria
4.1 General
This document specifies the minimum purity requirements for aluminium iron (III) chloride (monomeric) and
aluminium iron (III) chloride hydroxide (monomeric) used for the treatment of water intended for human
consumption. Limits are given for impurities commonly present in the products. Depending on the raw material and
the manufacturing process other impurities may be present and, if so, this shall be notified to the user and when
necessary to relevant authorities.
NOTE Users of these products should check the national regulations in order to clarify whether it is of appropriate purity for
treatment of water intended for human consumption, taking into account raw water quality, required dosage, contents of other
impurities and additives used in the products not stated in this product standard.
Limits have been given for impurities and chemical parameters where these are likely to be present in significant
quantities from the current production processes and raw materials. If the production process or raw materials
leads to significant quantities of impurities, by-products or additives being present, this shall be notified to the user.
4.2 Composition of commercial product
The concentration of active matter (aluminium ion content) expressed as grams per kilogram of product (Al g/kg)
shall be greater than 40 g/kg. The contents of aluminium and iron shall be within ± 3 % of the manufacturer's
declared values. The ratio Fe/Al shall be less than 0,50 for aluminium iron (III) chloride hydroxides (monomeric)
and less than 1,0 for aluminium iron (III) chlorides (monomeric).
The relative basicity, expressed as the mole ratio OH/3(Al + Fe), shall be within the range 0 to 0,35 for aluminium
iron (III) chloride hydroxides (monomeric). For aluminium iron (III) chloride (monomeric), the basicity is zero.
Aluminium iron (III) chloride (monomeric) often have a free acidity.
4.3 Impurities and main by-products
The content of insoluble matter shall be lower than 25 g/k
...