Analytical test methods for drinking water contact materials

The tests required under the Drinking Water Directive are carried out in accordance with specific European standards EN, which define the test methods used to assess the performance of materials in contact with drinking water.

The main methods used include:

Organoleptic assessments

• EN 1420 – contact tests for assessing changes in the organoleptic properties of water
• EN 1622 – determination of odour and flavour in water (TON – Threshold Odour Number, TFN – Threshold Flavour Number)

Physico-chemical parameters

• EN 7887 – determination of water colour
• EN 7027 – determination of turbidity

Migration testing from materials

• EN 12873-1 / EN 12873-2 – migration testing of organic materials and components

Determination of organic carbon

• EN 1484 – determination of Total Organic Carbon (TOC)

Screening for unexpected substances

• EN 15768 – identification of unexpected substances by GC-MS

Specific testing for metallic materials

• EN 16058 – testing of metal release from taps and metallic components

Assessment of microbial growth

• EN 16421 – assessment of enhanced microbial growth on materials

The Comie laboratory is accredited to perform all these test methods, ensuring full coverage of the analytical requirements established by European legislation for drinking water contact materials.

The tests to be performed vary depending on the type of material used in the product:

• organic materials (plastics, elastomers)
• metallic materials
• cementitious materials
• enamels and ceramic materials

The following table provides a detailed overview of the test methods applicable to the different material categories covered by European legislation.

For organic materials, the legislation provides for the classification of products and components into risk groups (RG).

The classification is carried out using a conversion factor (CF) specified in Table 5 of the fourth act under the Drinking Water Directive.

The conversion factor makes it possible to estimate, based on migration test results, the expected concentration of substances released into drinking water.

Depending on the conversion factor value, the product is assigned to a specific risk group, as defined in Table 1 of the fourth act of the legislation.

This classification determines:

• which tests must be performed
• whether testing must be carried out on the finished product, the component, or material test specimens

The definition of the required testing programme is managed by the certification body responsible for conformity assessment.

In the case of metallic materials, in addition to verifying the alloy composition, further testing may be required if the surface structure of the material has been modified.

This may occur, for example, in the presence of:

• welds
• electroplated coatings
• heat treatments
• surface coatings

In these cases, release testing for relevant substances is required in order to verify that the material does not release contaminants into drinking water.

The tests required under European legislation must be performed by laboratories accredited in accordance with EN ISO/IEC 17025:2017.

The Comie laboratory is accredited for all the analytical methods required by Commission Implementing Decision (EU) 2024/368, enabling manufacturers to carry out the entire testing programme required for the conformity of drinking water contact materials at a single laboratory.

Comie supports manufacturers in:

• defining the testing programme
• performing migration tests
• interpreting analytical results
• providing technical support throughout the certification process for drinking water contact materials