prEN 18279
(Main)Soil improvers and growing media - Enumeration of enterococci
Soil improvers and growing media - Enumeration of enterococci
This document specifies a method for the enumeration of enterococci in soil improvers and growing media. This document is applicable to material in solid form (including pre-shaped growing media) and liquid form.
This document is applicable to fertilizing product blends, where a blend is a mix of two or more fertilising products belonging to the categories of fertilizers, liming material, soil improvers, growing media, inhibitors and plant biostimulants, and where soil improvers and/or growing media comprise the highest percentage in the blend by mass or volume, or in the case of liquid form by dry mass. If soil improvers and/or growing media do not comprise the highest percentage in the blend, the European Standard for the highest percentage in the blend applies. In case a blend is composed of fertilising products in equal quantity, the user of the standard decides which standard to apply.
NOTE 1 A soil improver or a growing medium consists of a single bulky (volume-building) component or a mix of bulky (volume-building) components (for example peat, wood fibres, coconut coir, compost, expanded perlite).
NOTE 2 This method has been validated in an interlaboratory study with specific products that were present on the market during the study (Annex C).
Bodenverbesserungsmittel und Kultursubstrate - Zählung von Enterococcacae
Dieses Dokument legt ein Verfahren zur Zählung von Enterokokken in Bodenverbesserungsmitteln und Kultursubstraten fest. Dieses Dokument gilt für Material in fester Form (einschließlich vorgeformter Kultursubstrate) und in flüssiger Form.
Dieses Dokument ist für Düngeproduktmischungen anwendbar, wenn die Mischung aus mindestens zwei Düngeprodukten der folgenden Kategorien besteht: Düngemittel, Kalkdünger, Bodenverbesserungsmittel, Kultursubstrate, Hemmstoffe und Pflanzen-Biostimulanzien, sowie wenn Bodenverbesserungsmittel und/oder Kultursubstrate die Bestandteile mit dem höchsten Massen- oder Volumenanteil in der Mischung oder, im Fall von flüssiger Form, dem höchsten Trockenmasseanteil sind. Wenn Bodenverbesserungsmittel und/oder Kultursubstrate nicht den höchsten prozentualen Anteil in der Mischung ausmachen, ist die für den Bestandteil mit dem höchsten prozentualen Anteil in der Mischung geltende Europäische Norm anwendbar. Falls eine Mischung aus in gleicher Menge gemischten Düngeprodukten besteht, entscheidet der Anwender, welche Norm angewendet wird.
ANMERKUNG 1 Ein Bodenverbesserungsmittel oder Kultursubstrat besteht aus einem einzigen schüttfähigen (Volumen aufbauenden) Bestandteil oder aus einem Gemisch schüttfähiger (Volumen aufbauender) Bestandteile (z. B. Torf, Holzfasern, Kokosfasern, Kompost, Blähperlit).
ANMERKUNG 2 Dieses Verfahren ist im Rahmen eines Ringversuchs anhand von spezifischen Produkten, die im Zeitraum der Studie auf dem Markt verfügbar waren, validiert worden (Anhang C).
Amendements du sol et supports de culture - Dénombrement des entérocoques
Le présent document spécifie une méthode de dénombrement des entérocoques dans les amendements du sol et les supports de culture. Le présent document s’applique aux matériaux se présentant sous forme solide (y compris les supports de culture préformés) et sous forme liquide.
Le présent document est applicable aux mélanges de produits fertilisants constitués d’au moins deux produits fertilisants appartenant aux catégories suivantes : engrais, amendements minéraux basiques, amendements du sol, supports de culture, inhibiteurs et biostimulants des végétaux et, dans lesquels les amendements du sol et/ou les supports de culture sont les composants qui représentent le pourcentage le plus élevé du mélange en masse ou en volume, ou dans le cas d’un liquide, en masse sèche. Si les amendements du sol et/ou les supports de culture ne représentent pas le pourcentage le plus élevé du mélange, la Norme européenne relative au composant ayant le pourcentage le plus élevé dans le mélange s’applique. Dans le cas où le mélange est constitué de produits fertilisants en quantité égale, l’utilisateur de la norme décide quelle norme appliquer.
NOTE 1 Un amendement du sol ou un support de culture se compose d’un seul composant volumineux (augmentant le volume) ou d’un mélange de composants volumineux (augmentant le volume) (par exemple, la tourbe, les fibres de bois, la fibre de coco, le compost, la perlite expansée).
NOTE 2 Cette méthode a été validée lors d’une étude interlaboratoires avec des produits spécifiques présents sur le marché lors de l’étude (Annexe C).
Soil improvers and growing media - Enumeration of enterococci
General Information
- Status
- Not Published
- Publication Date
- 28-Jun-2026
- Technical Committee
- CEN/TC 223 - Soil improvers and growing media
- Drafting Committee
- CEN/TC 223/WG 5 - Microbiology
- Current Stage
- 4010 - Start of draft translation - Enquiry
- Start Date
- 24-Oct-2025
- Completion Date
- 09-Oct-2025
Overview
prEN 18279 (CEN draft) specifies a harmonized method for the enumeration of enterococci in soil improvers and growing media. The standard covers both solid (including pre-shaped substrates) and liquid products and applies to fertilising product blends when soil improvers/growing media are the dominant component. The method is intended to support hygienic control, sanitation verification and regulatory compliance by providing a reproducible procedure to determine colony‑forming units (CFU) of enterococci per gram or millilitre.
Key topics and technical requirements
- Scope and applicability
- Applies to solid and liquid soil improvers and growing media, including blends (rules for which standard applies are given when blends contain multiple fertilising product types).
- Method validated in an interlaboratory study (Annex C).
- Principle
- Spread plating of initial suspension or decimal dilutions onto Slanetz‑Bartley agar; incubation at 37 °C for ~46 h to enumerate presumptive enterococci (formazan-positive colonies).
- Confirmation of presumptive colonies on Bile Esculin Azide (BEA) agar at 44 °C to demonstrate esculin hydrolysis (blackening).
- Results expressed as CFU per g or mL following defined counting rules.
- Sampling and sample prep
- Sampling is outside the method; follow EN 12579 and sample preparation per prEN 13040-2.
- Equipment and reagents
- Typical microbiology lab equipment: incubators (37 °C, 44 °C), autoclave, water bath (47–50 °C), sterile pipettes, spreaders, Petri dishes, media prepared as per Annex B.
- Quality and validation
- Guidance on plate selection, colony counting limits, confirmation criteria, and method performance characteristics (Annex C).
- Recommendations for media performance testing per EN ISO 11133.
- Safety
- Tests must be done in properly equipped labs under skilled supervision; standard references EN ISO 7218 for microbiological practice.
Applications and who uses it
- Microbiology laboratories performing routine hygiene testing of substrates and growing media.
- Manufacturers of soil improvers, composts, peat, wood fibre, coconut coir and pre‑mixed growing media for internal quality control.
- Third‑party testing and certification bodies verifying compliance with hygienic limit values (e.g., Regulation (EU) 2019/1009).
- Regulators, plant health authorities and agronomy consultants monitoring faecal contamination indicators and sanitation process effectiveness.
- Useful in product development, process validation, factory sanitation audits and research on microbial safety of growing media.
Related standards
- EN 12579 (Sampling of soil improvers and growing media)
- prEN 13040-2 (Sample preparation for microbiological examination)
- prEN 17732 (Terminology)
- EN ISO 7218 (Microbiology of the food chain - general lab practice)
- EN ISO 11133 (Media performance testing) and ISO/ISO 5725 guidance for validation
Keywords: enterococci enumeration, soil improvers, growing media, Slanetz‑Bartley agar, Bile Esculin Azide, CEN standard, microbiological testing, fertilising product blends.
Frequently Asked Questions
prEN 18279 is a draft published by the European Committee for Standardization (CEN). Its full title is "Soil improvers and growing media - Enumeration of enterococci". This standard covers: This document specifies a method for the enumeration of enterococci in soil improvers and growing media. This document is applicable to material in solid form (including pre-shaped growing media) and liquid form. This document is applicable to fertilizing product blends, where a blend is a mix of two or more fertilising products belonging to the categories of fertilizers, liming material, soil improvers, growing media, inhibitors and plant biostimulants, and where soil improvers and/or growing media comprise the highest percentage in the blend by mass or volume, or in the case of liquid form by dry mass. If soil improvers and/or growing media do not comprise the highest percentage in the blend, the European Standard for the highest percentage in the blend applies. In case a blend is composed of fertilising products in equal quantity, the user of the standard decides which standard to apply. NOTE 1 A soil improver or a growing medium consists of a single bulky (volume-building) component or a mix of bulky (volume-building) components (for example peat, wood fibres, coconut coir, compost, expanded perlite). NOTE 2 This method has been validated in an interlaboratory study with specific products that were present on the market during the study (Annex C).
This document specifies a method for the enumeration of enterococci in soil improvers and growing media. This document is applicable to material in solid form (including pre-shaped growing media) and liquid form. This document is applicable to fertilizing product blends, where a blend is a mix of two or more fertilising products belonging to the categories of fertilizers, liming material, soil improvers, growing media, inhibitors and plant biostimulants, and where soil improvers and/or growing media comprise the highest percentage in the blend by mass or volume, or in the case of liquid form by dry mass. If soil improvers and/or growing media do not comprise the highest percentage in the blend, the European Standard for the highest percentage in the blend applies. In case a blend is composed of fertilising products in equal quantity, the user of the standard decides which standard to apply. NOTE 1 A soil improver or a growing medium consists of a single bulky (volume-building) component or a mix of bulky (volume-building) components (for example peat, wood fibres, coconut coir, compost, expanded perlite). NOTE 2 This method has been validated in an interlaboratory study with specific products that were present on the market during the study (Annex C).
prEN 18279 is classified under the following ICS (International Classification for Standards) categories: 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
prEN 18279 is associated with the following European legislation: EU Directives/Regulations: 2003/2003, 2019/1009; Standardization Mandates: M/564, M/564 AMD 1, M/564 AMD 2, M/588, M/XXX. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
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