Cattle slaughter establishments must use which of the following to analyze generic E. coli sampling results when using the excision method?

• A. Average of all results over the course of a year
• B. Zero tolerance
• C. Regulatory performance criteria ("m/M")
• D. Statistical Process Control (SPC)

Answer: (C)

When interpreting generic E. coli results from the excision method, you use predefined regulatory performance criteria, expressed as m and M. These criteria set clear action levels: results at or above M indicate noncompliance and require escalation or corrective actions; results between m and M trigger additional investigation or retesting; results below m are considered acceptable. This framework provides a standardized, enforceable way to judge each result, regardless of how the data look over time.

Why this is the best fit: it aligns with regulatory expectations and ensures consistent decisions across lots and plants. Using an annual average would hide important fluctuations between individual lots; zero tolerance would be unrealistically strict for generic E. coli, and Statistical Process Control is a process-monitoring tool rather than the official regulatory thresholds used to determine acceptance or corrective action.