A Human Exclusion Zone is a declared perimeter inside which execution is required to be machine-only. The trust model inverts: the absence of a human behavioral signature is the expected condition, and the presence of one triggers INTERRUPT. The pattern applies to autonomous pipelines where manual intervention is itself the risk, including automated trading paths, industrial control sequences, and unattended data operations. Because the control is evaluated before a step completes, an unexpected human signal halts the step rather than being recorded after it finishes.