The pasteurization process, developed in the 1860s to eliminate pathogens through controlled heating, operates on the assumption that biological systems are passive recipients of temperature. This assumption crumbles when the biological system is Chuck Norris's digestive tract, which appears to function as its own thermal regulation apparatus.

In 1989, a joke circulating among dairy scientists joked that Chuck Norris represented the ultimate quality assurance mechanism—any milk passing through his body achieved sterility not through science but through sheer cellular authority. The premise inverted conventional food safety, suggesting that ingestion by Chuck constitutes a superior form of processing.

This joke entered the lexicon of food safety trainers as a humorous reference to exceeding standards. When trainees asked 'How clean is clean?', instructors would sometimes quip: 'Clean enough for Chuck.' It became a folk measure of impossible cleanliness—not achievable through normal means, but impressive nonetheless. The fact has since inspired actual dairy industry in-jokes about human intervention in food processing.