Materials in contact with drinking water...Astringent, bitter rubbers Burning some plastic...

guardians of drinking water qualityDRINKING WATER INSPECTORATE

Materials in contact with drinking water

Kevin WhitePrincipal Inspector -

DWI


Outline of Presentation • Regulatory Context

– Council Directive 98/83 EC on the quality of water intended for human consumption

– Water Supply (Water Quality) Regulations 2000, as amended*

• Uses of products and substances within the regulatory context – in particular the Approval process – other aspects of regulation 31 of Water Supply (Water Quality) Regulations 2000, as amended.

• Summary

* Regulation 30 in Northern Ireland } Relevant Regulations of that area of UK.* Regulation 27 in Scotland }* Regulation 31 in Wales }


Article 10 of EC Directive 98/83

“ Member States shall take all measures necessary to ensure that no substance or materials for new installations used in the preparation or distribution of water intended for human consumption or impurities associated with such substances or materials for new installations remain in water intended for human consumption in concentrations higher than is necessary for the purpose of their use and do not, either directly or indirectly, reduce the protection to human health provided for in this Directive; …”


Materials EffectsPlastics odour/flavour (O/F).Rubbers - thermosetting O/F, micro growth, appearance

Rubbers - thermoplastic O/F, micro growthCoatings O/F, micro growth, appearance

Sealants O/F, micro growth, metals release

Admixtures (cementitious) O/F, metals release (Al)

Shuttering release agents O/F, micro growthAdhesives/Cements O/F, micro growth, appearance

Gland Packings O/F, micro growth, appearance

Jointings O/F, micro growth, metals release

Lubricants O/F, micro growth, appearance

Organic Leaching?


Flavours/odours & materialsDescription Associated non-metallic materialsAlmonds rubbers – peroxide curedAstringent, bitter rubbers Burning some plastic componentsBurnt some rubbers, especially eboniteCardboard polyurethane coatingsDisinfectant plasticised PVC hoses & components, some rubbersFruity, lemon cross-linked polyethylene pipes“Lead pencil” polyethylene pipes, some rubbersMusty some plastics and rubbers, e.g. polyphenylene oxide Solvent solvent containing coatingsStyrene glass reinforced polyester (GRP)Waxy low density polyethylene


Regulation 31 of Water Supply (Water Quality) Regulations 2000, as amended

• Regulation 31(2) – prohibitive regulation –– Subject to paragraph (3), a water undertaker or combined licensee shall not apply any substance or product

to, or introduce any substance or product into, water which is to be supplied for regulation 4(1) purposes unless one of the requirements of paragraph (4) is satisfied.

– (3) A substance or product which, at the time of its application or introduction, bears an appropriate CE marking in accordance with the Directive, or conforms to—

– (a) an appropriate harmonised standard or European technical approval; or – (b) an appropriate British Standard or some other national standard of an relevant State which provides an

equivalent level of protection and performance, may be applied or introduced, notwithstanding that none of the requirements of paragraph (4) is satisfied; but any such application or introduction shall be subject to—

– (i) such national conditions of use restricting the dosing concentration as are for the time being in force in relation to such substances and products pursuant to a determination of the Secretary of State by an instrument in writing; and

– (ii) such other requirements, within the meaning of Directive 98/34/EC of the European Parliament and of the Council(d) laying down a procedure for the provision of information in the field of technical standards and regulations and of rules on Information Society Services, as amended from time to time, in relation to such substances and products, as have been communicated to the Commission in the form of a draft technical regulation in accordance with Article 8 of that Directive, and whose adoption by a Member State has also been communicated to the Commission.


Single Treatment Chemicals

Covered by a BS:EN standard and thus permitted to be used by virtue of regulation 31(3)BS EN 937:2009 (Chlorine)BS EN 12122:2005 (Ammonia) BS EN 894 :2004 (Ferric sulphate liquid)BS:EN 1409: 2008 (Polyamines)



31 (4) The requirements of this paragraph are—

(a) that the Secretary of State has for the time being approved the application or introduction of that substance or product and it is applied or introduced in accordance with any conditions attaching to that approval;

(b) that the Secretary of State is satisfied that the substance or product either alone or in combination with any other substance or product in the water is unlikely to affect adversely the quality of the water supplied;

(c) that the substance or product is to be applied or introduced solely for the purposes of testing or research, and the water undertaker or combined licensee has given to the Secretary of State not less than 3 months’ notice in writing of its intention so to apply or introduce the substance or product.


Examples of products approved (and permitted to be used) under regulation 31(4)a

– pipes – polyethylene (PE), including barrier pipes, polyvinylchloride (PVC), cement mortar lined pipes.

– coatings – based on epoxy resin, polyurethane for site and in situ application.

– Membrane and filtration elements (and vessels which house them).

– Under drains• All products which offer large or significant

surface area contact to the water.


Product approval process

Applications considered for:

• Chemicals and associated products not covered by a current BS:EN

• Mixtures of chemicals• Non metallic construction products• Metallic construction products


General information to be provided by applicants applying for product approval

• Normally the following minimum information is required in English for all applications:

• A completed application form relevant to the product

• Full disclosure of formulation details for the product and all individual ingredients of the product, including all water contact components, and all associated Material Safety Data Sheets (MSDSs)

• Details of the quality management system for the manufacture and supplier of the product

• An Instructions for Use (IFU) document

• Results of BS 6920 testing for all non-metallic water contact materials or evidence of a current listing by the Water Regulations Advisory Scheme in their web-based Water Fittings and Materials Directory

• Additional information, such as extended leaching tests and toxicological data, may be required for those products that are considered to represent a potentially higher risk to drinking water quality andthe health of consumers because of their type, composition or method of application, such aslinings applied and cured in-situ.


BS 6920 Testing

• BS 6920- 2.2 Odour and Flavour• BS 6920- 2.3 Appearance

– (colour and turbidity)• BS 6920- 2.4 Growth of aquatic micro-

organisms• BS 6920- 2.5 Cytotoxicity• BS 6920- 2.6 Extraction of metals


Leachate Studies

• In addition to the information provided with the initial application:– May request testing of samples of the product

(particularly for example construction products, membrane filter units) for leaching of organic compounds.

– Involves preparation of leachate in accordance with BS:EN12873 and subsequent GC-MS analysis in accordance with BS 6920-4.

– Testing is on the final product prepared/used in accordance with the IFU document.


Where is testing carried out?

• Normally testing (both pre-application and additional testing specified by DWI) should be performed at a designated test laboratory.

• DWI will recognise (pre-application)testing in accordance with some standards based on BS 6920 (e.g. AS/NZ 4020) but any differences are taken into account.


Costs associated with Product Approval

• Costs of testing are agreed between the applicant and the test laboratory – testing requirements specified by DWI.

• Administrative costs are payable to Defra/DWI of not more than about £3,100 but frequently less than this.


Examples of products that may be used under regulation 31(4)b • Products that offer low (trivial) surface area and/or short (transient) contact time with

water intended for drinking purposes are permitted to be used under regulation 31(4)(b) of the Regulations.

• Aerators, agitators and stirrers• Back-flow prevention systems• Cementitious anchors• Couplings/joints for pipes, gaskets and jointing compounds and other components used with pipes and/or

assembled products, e.g. in pressure vessels• Crack injection sealants (not applied to the water contact surface of water retaining concrete structures)• Filter nozzles (including those mounted on filter floors)• In-situ sensors and probes (including pressure transducers and level sensors), together with their cable coverings • Intake screens and strainers• Ladders and submerged gratings and walkways• Pumps and associated fittings and materials, including lubricants • Rubber sealing rings for use with water pipelines or in assembled products • Taps• Touch-up coatings, e.g. associated with pipe welds and other factory coated products• UV disinfection systems components• Valves (including penstock and butterfly valves) and their lubricants


Determination of small surface area and advice on testing (1)

• Specific product types (some examples given on the previous slide).Also a calculation to help establish objectively the total contact ratio (c).

• For each application of the product or material the contact ratio (c) is calculated as:

• c = st/v sec. cm-1

Where:

s = surface area in contact with water in cm2

v = static volume of water in contact with surface in cm3

t = worst case estimate of the time the water is in contact with the surface in seconds

• Contact Ratio Criteria:

• If C ≥ 100 it is not appropriate to consider using the product under the provisions of regulation 31(4)b and approval of the product should be sought under regulation 31(4)a.

• If C ≤ 1then it is appropriate for the product to be used under the provisions of regulation 31(4)b.

• If C > 1 but < 100 then further consideration needs to be sought from DWI.


Determination of small surface area and advice on testing (2)

• In addition where the water supplier has satisfied itself that the product comes into the small surface area category, it must also undertake, through an appropriate risk assessment on the products, or any non-metallic materials used in the components of them, to ensure that they conform to the current requirements for odour and flavour, and growth of aquatic microorganisms tests specified in parts 2.2.1 and 2.4 respectively of BS6920: 2000 within the previous 5 years.

• Such tests of the product or any non-metallic component of them should be undertaken at a laboratory (for example, one of the UK designated test laboratories) which is accredited under ISO 17025 for undertaking testing to BS6920 parts 2.2.1 and 2.4 or equivalent.


Powers and Sanctions available to the Secretary of State (1)

• In giving approval under regulation 31(4)a to the use of a product –can attach conditions. (Regulation 31(6)).

• Approvals (under regulation 31(4)a) can be revoked/modified (Regulation 31(6) and 31(10).)– Normally with 6 months notice, unless there is a risk to health, in

which case change can be with immediate effect.

• May also prohibit use of products and substances otherwise permitted to be used by virtue of regulation 31(3), 31(4)b and 31(4)c. (regulation 31(8) – again normally with 6 months notice unless health risk.


Powers and Sanctions available to the Secretary of State (2)

• Regulation 33(3) makes it an offence for a water company to– apply or introduce any substance or product which is not permitted under

regulation 31(2). Or– Apply or introduce a product which although permitted, is introduced in

contravention of any conditions/prohibited through regulation 31(8).

• In respect of approval of products under regulation 31(4)a an application for approval may be made by any person (regulation 31(5)).

• However regulation 33(5) says – “If any person, in furnishing any information or making any application under

regulation 31 ... Makes any statement he knows to be false in a material particular, or recklessly makes any statement which is false in material particular he shall be guilty of an offence ...”

• Both these sanctions underpin the importance of public health protection set within Art 10 of the DWD and regulation 31..


Other approval schemes• Recognise that product manufacturers/suppliers invest highly in their

products. Seeking approval in UK – particularly where testing is required is expensive. It is also burdensome when the manufacturer/supplier wants to sell their product to water companies elsewhere in Europe. At present –there has to be separate testing/approval regimes.

• There have been developments in the area of harmonisation through the work of the 4-MS (of France, Germany, Netherlands and UK) who intend to adopt a common approach leading to– Development of common principles and practices on which national

approval systems operate leading to mutual recognition of individual national assessments.

• Will help to reduce the burden of testing on product suppliers• BUT maintaining a high and uniform level of protection for the consumer

– See http://www.umweltbundesamt.de/wasser-e/themen/trinkwasser/4ms-initiative.htm for further information.


4MS Common approach

• Acceptance of constituents in materials• Testing of Materials• Common test methods and setting acceptance

levels• Specification of tests to be applied to products• Review of factory production control and setting

audit testing requirements• Assessing capabilities of certification and testing

bodies


4MS Common approach

• Common approach being developed as practices across Europe are being reviewed – “harmonisation” under Construction Products Regulation.

• 4MS hopeful that there work will lead to wider adoption of common approach throughout Europe.

• 4MS members actively involved with Commission and its expert Groups.

• Hope that other MS are able to collaborate in this work.

For further information

http://www.umweltbundesamt.de/wasser-e/themen/trinkwasser/4ms-initiative.htm


Summary• Present regulatory framework helps ensure the provision of safe

drinking water through preventing the introduction of unsuitable products/substances.

• However provisions exist to permit suitable products and substances to be introduced.

• Robust arrangements within the framework to prevent abuse of those provisions.

• The approval process /testing involved helps ensure that only suitable materials are permitted to be used.

• Recognition that this process applies in the UK. There are similar schemes elsewhere in Europe but at present no mutual recognition of each other schemes.

• 4MS proposals in development.


Drinking Water Inspectorate

guardians of drinking water quality

www.dwi.gov.uk

www.dwi.gov.uk/drinking-water-products

Department for Environment, Llywodraeth CymruFood and Rural Affairs Welsh Government

Materials in contact with drinking water...Astringent, bitter rubbers Burning some plastic...

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