Overview - ISO 19020:2017 for food testing and safety
ISO 19020:2017 specifies a horizontal screening method for the immunoenzymatic (EIA) detection of staphylococcal enterotoxins SEA, SEB, SEC (SECs), SED and SEE in foodstuffs. The standard defines a two‑step protocol: (1) extraction from food followed by concentration (dialysis‑based), and (2) detection using commercially available immunoenzymatic test kits. ISO 19020:2017 is aimed at screening products intended for human consumption and supports food safety monitoring and outbreak investigations.
Key topics and technical requirements
- Scope: Applicable for detection of SE types SEA–SEE; other SE types (SEG, SEH, SEI, etc.) may be covered only after validation and availability of kits.
- Two main steps:
- Extraction and concentration - typically a 25 g test portion, extraction with water at about 38 °C ± 2 °C, shaking 30–60 min (18–27 °C), acidification to pH 3.5–4.0, centrifugation at ≥ 3 130 g, followed by dialysis concentration (MWCO 6 000–8 000 Da).
- Immunoenzymatic detection - use of commercial EIA kits that comply with the method’s performance criteria (sensitivity, specificity, LOD50).
- Performance metrics: Definitions and targets for sensitivity (SE), specificity (SP) and limit of detection 50 (LOD50) are included; the standard references use of benchmark dose (BMD) approaches when setting detection limits.
- Quality control and reporting: Includes guidance on reagents, apparatus (rotary homogenizer, centrifuge, dialysis membrane, PEG 20 000 g/mol solution), storage, handling and expression of results. Test portion flexibility is allowed for outbreak samples with proportional scaling.
Practical applications and users
- Who uses ISO 19020:2017:
- Public health and food safety laboratories
- Regulatory agencies enforcing microbiological criteria
- Food manufacturers and quality control labs
- Third‑party testing service providers and reference laboratories
- Teams investigating suspected staphylococcal food poisoning outbreaks
- Why it’s useful:
- Standardizes sample preparation and immunoassay detection for reproducible screening
- Supports compliance with regulatory microbiological criteria and risk assessment
- Enables rapid screening of a wide range of food matrices (special concentration steps for milk/dairy)
Related standards and resources
- ISO 3696 - Water for analytical laboratory use (referenced for reagent quality)
- ISO 7218 - Microbiology of food and animal feeding stuffs: general lab requirements
- ISO 19020:2017 requires that selected immunoenzymatic kits meet the method’s performance criteria (see clause 8.7).
ISO 19020:2017 is a practical, standardized approach for detecting heat‑stable staphylococcal enterotoxins in foods, improving consistency in food microbiology testing and supporting food safety decision‑making.