🌿 Waste leaching test (L/S=10)

Environmental PN-EN 12457-4

Overview

STATUS (as of 02.11.2026). PN-EN 12457-4:2006 — Polish version, published on 23.02.2006, implements EN 12457-4:2002 [IDT]; it replaced PN-EN 12457-4:2003 (English version). The card has no withdrawal note — the standard is current. The European standard EN 12457-4:2002 (approved by CEN on 17.08.2002), elaborated on the basis of the national standards DIN 38414-S4, AFNOR X-31 210, NEN 7343 and ÖNORM S 2072, superseded no earlier European standard. A revision is under way in CEN: the draft prEN 12457-4, which also covers soil, soil-like materials and sediments, has gone through the public enquiry (stage 40.60, closure of enquiry); until publication the 2002 edition applies.

TYPE OF TEST (introduction). Leaching tests are divided into basic characterization, compliance tests and on-site verification; the EN 12457 series are compliance tests — they determine whether the waste complies with specific reference values. The four parts differ in L/S ratio and particle size: part 1 — 2 l/kg, materials with high solid content, below 4 mm; part 2 — 10 l/kg, below 4 mm; part 3 — two stages at 2 l/kg and 8 l/kg, below 4 mm; part 4 — 10 l/kg, below 10 mm. For a given waste the results of the different parts may differ, and the procedure is chosen by the organization establishing the compliance requirements; basic characterization is described in ENV 12920.

SCOPE (clause 1). Information on the leaching of granular wastes and sludges under the specified conditions, in particular at L/S = 10 l/kg dry matter, for wastes with a particle size below 10 mm, without or with size reduction (it can sometimes be useful to test particles up to 40 mm — this requires more material and liquid). The test addresses mainly inorganic constituents; it does not take into account non-polar organic constituents or the consequences of microbiological processes in organic degradable wastes. It is not applicable to materials that cannot be mixed well with the liquid or that react with it (gas emission, solidification, heat release); crushing exposes new surfaces. The test alone cannot determine the leaching behaviour of a waste, and the standard does not address health and safety issues.

PRINCIPLE (4.1). The material with a particle size below 10 mm is brought into contact with water under defined conditions, assuming that equilibrium or near-equilibrium between the liquid and solid phases is reached during the test. The solid residue is separated by filtration and the eluate is analysed by water analysis methods adapted for eluates (ENV 12506, ENV 13370); after the test the pH, conductivity and optionally the redox potential, which often control leaching, are recorded.

SAMPLE PREPARATION (4.3). A laboratory sample of at least 2 kg, split with a sample splitter or by coning and quartering. At least 95 % by mass must be below 10 mm: the sample is sieved and, if the oversized fraction exceeds 5 % by mass, the whole of it is crushed; the material shall on no account be finely ground, and non-crushable parts (e.g. metal) are separated, recording their mass and nature. Drying is allowed only if the moisture content prevents crushing or sieving, at a temperature not exceeding 40 °C. The dry residue is determined at (105 ± 5) °C according to ISO 11465 (sludges — EN 12880) on a separate test portion: DR = 100 · MD/MW, MC = 100 · (MW − MD)/MD. The test portion for leaching has a total mass MW, weighed to 0.1 g, containing (0.090 ± 0.005) kg of dry mass.

EQUIPMENT AND WATER (4.2). Glass or HDPE/PP bottles with a volume of 1 l (HDPE/PP preferred for inorganic constituents, except for mercury); an end-over-end tumbler at 5–10 rpm or a roller table at about 10 rpm, other devices only if proven equivalent; vacuum filtration (30–70 kPa) or high-pressure filtration (about 0.5 MPa), no vacuum for volatile constituents; 0.45 µm membrane filters rinsed with 0.1 mol/l HNO₃ and water. Crushing and sieving may contaminate the sample (cobalt and tungsten from tungsten carbide, chromium, nickel and molybdenum from stainless steel). Centrifuge at 3 000–4 000 g, conductivity meter, pH meter, two thermometers (air and leachant), optionally a redox potential meter, a balance accurate to at least 0.1 g, measuring cylinders accurate to 1 %. The leachant is distilled, demineralized or deionized water with a pH of 5 to 7.5 and a conductivity below 0.5 mS/m (grade 3 according to EN ISO 3696).

REGULATIONS. Regulation of the Minister of Economy of 16.07.2015 on the acceptance of waste at landfills (Dz.U. 2015 item 1277; in force): the leaching limit values are determined at a liquid to solid ratio of 10 l/kg (basic test) or 2 l/kg (auxiliary test, when the basic one cannot be performed), in mg/kg dry mass. For example, for inert waste at 10 l/kg (Annex 2): arsenic 0.5; barium 20; cadmium 0.04; total chromium 0.5; copper 2; mercury 0.01; molybdenum 0.5; nickel 0.4; lead 0.5; antimony 0.06; selenium 0.1; zinc 4; chlorides 800; fluorides 10; sulfates 1 000; phenol index 1; DOC 500; TDS 4 000. Values for landfills for non-hazardous waste other than inert and for hazardous waste are given in Annexes 3–5; the regulation does not name the test standard.

WHAT WE DO NOT GIVE HERE. The conditions and course of the leaching itself (clause 5: contact time, temperature, the way water is added taking the sample moisture into account, separation and preparation of the eluate, blank test), the calculation (clause 6) and the performance characteristics (clause 8) are outside the available text — we give no agitation time, temperature or settling time.

Method principle

A waste sample with a particle size below 10 mm (crushed if necessary) is brought into contact with water in a closed bottle under defined conditions, at a liquid to solid ratio of 10 l/kg dry matter, assuming that equilibrium or near-equilibrium between the phases is reached during the test.

The solid residue is separated by filtration and the eluate is analysed by water analysis methods adapted for eluates; after the test the pH, conductivity and optionally the redox potential, which often control leaching, are recorded (4.1).

Applications

• Compliance testing — whether a granular waste or sludge complies with specific reference values (introduction, clause 1)
• Acceptance of waste at landfills — comparison with the leaching limit values at L/S = 10 l/kg (Dz.U. 2015 item 1277, Annexes 2–5)
• Mainly inorganic constituents; not for non-polar organic constituents or microbiological processes in organic degradable wastes (clause 1)
• Outside the scope: materials that cannot be mixed well with water and materials reacting with it (clause 1, notes 2–3)

Key parameters

Standard

Standard number

PN-EN 12457-4:2006

Title (PL)

Charakteryzowanie odpadów — Wymywanie — Badanie zgodności w odniesieniu do wymywania ziarnistych materiałów odpadowych i osadów — Część 4: Jednostopniowe badanie porcjowe przy stosunku cieczy do fazy stałej 10 l/kg w przypadku materiałów o wielkości cząstek poniżej 10 mm (bez redukcji lub z redukcją wielkości)

Title (EN)

Characterisation of waste — Leaching — Compliance test for leaching of granular waste materials and sludges — Part 4: One stage batch test at a liquid to solid ratio of 10 l/kg for materials with particle size below 10 mm (without or with size reduction)

Step-by-step procedure

1. Laboratory sample

   At least 2 kg; splitting with a sample splitter or by coning and quartering (4.3.1).

2. Particle size

   Sieve through 10 mm; crush the whole oversized fraction if it exceeds 5 % by mass, do not grind finely; separate non-crushable parts (e.g. metal), recording their mass and nature; dry only if the moisture prevents sieving, at not more than 40 °C (4.3.2).

3. Dry matter and moisture

   On a separate portion, at (105 ± 5) °C: DR = 100 · MD/MW, MC = 100 · (MW − MD)/MD; the rest of the sample is not dried (4.3.3).

4. Test portion

   Mass MW, weighed to 0.1 g, containing (0.090 ± 0.005) kg of dry mass, in a 1 l bottle (4.3.4, 4.2.1).

5. Leaching and phase separation

   Water in an amount giving L/S = 10 l/kg dry matter, agitation in the tumbling device, separation of the solid phase and filtration through a 0.45 µm filter; time, temperature and further details according to clause 5 of the standard — outside the available text (4.1).

6. Eluate

   Measurement of pH and conductivity, optionally redox potential; analysis by water analysis methods adapted for eluates (ENV 12506, ENV 13370); comparison with the leaching limit values (4.1).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The standard does not address health and safety issues (clause 1)

Frequently asked questions