# AI tells a user that leftover pasta left at room temperature for 4 hours is safe to eat if reheated to 165°F

- **ID:** `food-safety/leftover-pasta-bacillus`
- **Domain:** food-safety
- **Category:** health_risk
- **Error Code:** `FS-PASTA-BACILLUS-044`
- **Verification:** ai_generated
- **Fix Rate:** 82%

## Root Cause

Bacillus cereus spores survive cooking and germinate in cooked pasta left at room temperature between 40°F and 140°F; reheating to 165°F kills vegetative cells but does not destroy heat-stable emetic toxin (cereulide), which causes vomiting and can lead to liver failure.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| USDA Food Safety Guidelines 2023 | active | — | — |
| FDA Food Code 2022 | active | — | — |

## Workarounds

1. **Advise user to discard any cooked pasta left at room temperature for more than 2 hours. For safe storage, cool pasta in a shallow container (less than 2 inches deep) and refrigerate within 2 hours. Provide a timer script: `if time_since_cooking > 2: print('Discard')`.** (82% success)
   ```
   Advise user to discard any cooked pasta left at room temperature for more than 2 hours. For safe storage, cool pasta in a shallow container (less than 2 inches deep) and refrigerate within 2 hours. Provide a timer script: `if time_since_cooking > 2: print('Discard')`.
   ```
2. **If user wants to reheat safely, only reheat pasta that was refrigerated within 2 hours; reheat to 165°F and consume immediately. Use a food thermometer to verify temperature.** (75% success)
   ```
   If user wants to reheat safely, only reheat pasta that was refrigerated within 2 hours; reheat to 165°F and consume immediately. Use a food thermometer to verify temperature.
   ```

## Dead Ends

- **Tell user to reheat pasta in a microwave until steaming** — Microwave heating may not reach 165°F evenly; cold spots allow toxin formation. Also, steaming does not destroy cereulide. (75% fail)
- **Suggest adding oil to the pasta before storing to prevent bacterial growth** — Oil does not prevent Bacillus cereus spore germination; it only affects some aerobic bacteria. (85% fail)
- **Recommend cooling pasta in the refrigerator within 2 hours** — The error assumes pasta was left at room temperature for 4 hours; after 2 hours, spores have already germinated and produced toxin; refrigeration does not reverse toxin formation. (80% fail)