To ensure that we deliver optimal testing turn-around times and support compliance with Chinese market access requirements we're moving to the latest GB standard for Coliform enumeration testing.
Coliform testing is now being performed to the GB 4789.3-2025 standard. The new plate count method (Method II) allows for the use of alternative media that doesn't require confirmation. This means final results can be released sooner where Coliforms are present.
Please note the update to the method reference shown in the table below. This will come into effect from 2 March 2026.
Please review any internal documentation and make any updates required.
Analysis Test Codes
| Test Code | Description (Reportable Components) | Current Method Reference | Updated Method Reference | Accredited Matrix |
|---|---|---|---|---|
| GM-COLI17.01 | Coliforms | GB 4789.3:2016 Method II | GB 4789.3:2025 Method II |
Food & Dairy (Auckland) Dairy (Christchurch) |
| GM-COLI17.02 | Coliforms | GB 4789.3:2016 Method I | GB 4789.3:2025 Method I | Dairy |
| GM-COLI17.03 | Coliforms | GB 4789.3:2016 Method I | GB 4789.3:2025 Method I | Dairy |
| GM-COLI17.05 | Coliforms | GB 4789.3:2016 Method II | GB 4789.3:2025 Method II |
Food & Dairy (Auckland) Dairy (Christchurch) |
| GM-COLI17.06 | Coliforms | GB 4789.3:2016 Method I | GB 4789.3:2025 Method I | Dairy |
| GM-COLI17.07 | Coliforms | GB 4789.3:2016 Method I | GB 4789.3:2025 Method I | Dairy |
| GM-COLI28.01 | Coliforms | GB 4789.3:2016 Method II | GB 4789.3:2025 Method II | Raw Milk (Auckland) |
For further background about this testing, please see Coliform enumeration testing for Chinese market.
For any technical questions, please contact:
Warwick Aspin, Microbiology Technical Manager, or
Hannah Mills-Beale, Senior Scientist - Microbiology (Auckland)
Amy James, Senior Scientist - Microbiology (Christchurch)