Overview
EN ISO 4833-2:2013/A1:2022 (CEN endorsement of ISO 4833-2:2013/Amd 1:2022) is an amendment that clarifies the scope of the horizontal method for the enumeration of microorganisms by colony count at 30 °C using the surface plating technique. The standard specifies a horizontal, aerobic surface-plating method for microorganisms able to form colonies on solid media after incubation at 30 °C and confirms intended application across the food chain.
Key topics and technical requirements
- Method type: Horizontal method - colony count by surface plating (manual spread plating) and includes the use of an automated spiral plater (see Annex A) for surface colony counts.
- Incubation conditions: Aerobic incubation at 30 °C.
- Organisms covered: Microorganisms able to grow and form colonies on the surface of solid medium under the specified conditions.
- Minimum count guideline: Technique is suitable for samples that yield a minimum of 10 colonies per plate, corresponding broadly to expected levels of >100 cfu/ml for liquid samples or >1 000 cfu/g for solid samples.
- Scope of application: Applies to products intended for human consumption, products for animal feeding (including pets), environmental samples from food and feed production/handling areas, and all samples from primary production.
- Suitability notes and limitations: Especially suited to samples with heat‑sensitive organisms (e.g., psychrotrophs), obligately aerobic bacteria (e.g., Pseudomonas species), samples with small particles or intense colour that hamper pour-plate reading, and when colony-type differentiation is required. The amendment notes limited suitability for some fermented foods and certain animal feeds; alternative media or incubation conditions may be more appropriate for those products.
Applications and who uses it
- Quality control and microbiology laboratories performing routine total viable counts for foods and feed.
- Food safety and QA/QC teams in food manufacturing (fresh, chilled, frozen, dried foods).
- Feed producers and animal-health labs monitoring feed hygiene.
- Environmental monitoring programs in food and feed production and handling facilities.
- Primary producers and regulators requiring standardized colony-count methods for compliance and surveillance.
Related standards and context
- This amendment is part of the ISO 4833 series (Microbiology of the food chain). It was approved by CEN and is to be implemented as a national standard across CEN member states. The document emphasizes minimizing deviations from the horizontal method so results remain comparable across applications.
Keywords: EN ISO 4833-2:2013/A1:2022, colony count 30 °C, surface plating technique, horizontal method, enumeration of microorganisms, food microbiology, spiral plater, cfu/ml, cfu/g.
