Overview
EN ISO 8795:2001 - "Plastics piping systems for the transport of water intended for human consumption - Migration assessment" - specifies a laboratory method to determine migration values from the internal surfaces of plastic pipes, fittings and joints. The standard is focused on chemical migration (extractability) into water; organoleptic and microbiological assessments are excluded. It applies to all plastics products used for drinking water and raw water used to produce drinking water.
Key topics and technical requirements
- Scope: Measures constituents extractable by water from finished pipes, fittings and joints; covers procedures for small and large nominal sizes (Annex B).
- Test principle: Test pieces undergo stagnation and prewashing with tap water, then are exposed to specified test liquids at defined temperatures for set migration periods; the migration liquid is analyzed to quantify migrated constituents.
- Test liquids (Annex A): several defined waters including neutral, acidic (pH 4.5), alkaline (pH 9 and pH 11), and chlorinated variants (e.g., 1 ± 0.2 mg/l active chlorine). Test liquids must have negligible interfering substances (EN ISO 3696 referenced).
- Test temperatures (clause 6): typical choices include (23 ± 2) °C for cold water, (60 ± 2) °C or (70 ± 2) °C for warm water (pipe-class dependent), (90 ± 2) °C for hot water and (27 ± 2) °C for tropical conditions.
- Exposure times: the method includes stagnation periods; exposure times are specified (e.g., 72 h for cold water, 24 h for warm/hot applications as noted in the foreword).
- Surface-area-to-volume (S/V) ratio: the S/V shall be not less than 5 dm² per litre to ensure representative migration values.
- Definitions & outputs: migration value (M) = mass of constituents migrated per defined surface area; migration number (n) = number of sequential migrations performed.
- Apparatus & materials: use inert materials (glass, PTFE, stainless steel) for containers and connections; thermostatically controlled environments for temperature control.
- Documentation: specifies required test report content and analytical accuracy considerations.
Applications and who uses it
- Manufacturers of plastic pipes, fittings and joints use EN ISO 8795:2001 to verify product safety and conformity for drinking-water use.
- Test laboratories adopt the method for routine migration testing and product certification.
- Regulators and conformity assessment bodies reference it when setting compliance criteria or approving products under national/EU drinking-water rules (e.g., Directive 98/83/EC is related to pH conditions).
- Water utilities, installers and specifiers may rely on results to select materials with low migration for potable water systems.
Related standards
- EN ISO 3696 (Water for analytical laboratory use) - referenced for test-water quality.
- ISO 7393-2 (Chlorine determination) - referenced for chlorinated test liquids.
- Supersedes EN 852-1:1996; aligns with ISO/TC 138 work on plastics piping systems.
Keywords: EN ISO 8795:2001, migration assessment, plastics piping systems, drinking water, migration values, test liquids, S/V ratio, pipes fittings joints.
