What are 'TCS foods' and why are they important to food managers?

TCS foods (formerly called Potentially Hazardous Foods/PHF) require strict time and temperature controls because their characteristics support pathogen growth or toxin formation. Characteristics that make foods TCS: (1) High water activity (Aw > 0.85); (2) Neutral or slightly acidic pH (4.6-7.5); (3) Protein-rich. Specific TCS foods per FDA Food Code: animal-based foods (meat, poultry, fish, shellfish, eggs, dairy); cooked plant-based foods (rice, beans, vegetables, pasta — once cooked, the matrix supports growth); cut leafy greens; cut tomatoes; cut melons; raw seed sprouts; garlic-in-oil mixtures (anaerobic, supports Clostridium botulinum); soy-protein products (tofu, soy milk); untreated garlic-in-oil; certain plant foods that have been heat-treated. Non-TCS foods: low Aw (dry foods, jam), low pH (most pickles, mayonnaise), or with effective preservation. Why important: Temperature Danger Zone is 41°F to 135°F (5°C to 57°C); TCS foods cannot be in this zone more than 4 hours total (or 6 hours per FDA Food Code if temperature monitored). Cold holding ≤41°F; hot holding ≥135°F. Time as a Public Health Control (TPHC) — using time alone instead of temperature — requires written procedures, marking, and 4 or 6 hour maximums.