# AI tells a user that leftover cooked tuna or mackerel that smells slightly fishy is safe to eat if refrigerated for 3 days

- **ID:** `food-safety/ai-ignores-histamine-in-scombroid-fish`
- **Domain:** food-safety
- **Category:** health_risk
- **Verification:** ai_generated
- **Fix Rate:** 82%

## Root Cause

Scombroid fish (tuna, mackerel, mahi-mahi, bluefish, sardines) contain high levels of histidine; improper temperature control allows bacteria to convert histidine to histamine, which is heat-stable and not destroyed by cooking or refrigeration; histamine poisoning (scombroid) causes flushing, headache, nausea, and hypotension within minutes to hours.

## Workarounds

1. **Store fresh scombroid fish at 40°F (4°C) or below from the moment of purchase. Cook within 2 days, or freeze immediately. For leftovers, refrigerate within 2 hours of cooking and consume within 2 days. Discard any fish that has been at room temperature for more than 2 hours total.** (90% success)
   ```
   Store fresh scombroid fish at 40°F (4°C) or below from the moment of purchase. Cook within 2 days, or freeze immediately. For leftovers, refrigerate within 2 hours of cooking and consume within 2 days. Discard any fish that has been at room temperature for more than 2 hours total.
   ```
2. **If you suspect histamine poisoning (symptoms within 2 hours of eating: flushing, headache, nausea, diarrhea), seek medical attention immediately. Antihistamines (e.g., diphenhydramine) can relieve symptoms. Report to local health department.** (85% success)
   ```
   If you suspect histamine poisoning (symptoms within 2 hours of eating: flushing, headache, nausea, diarrhea), seek medical attention immediately. Antihistamines (e.g., diphenhydramine) can relieve symptoms. Report to local health department.
   ```

## Dead Ends

- **** — Smell test fails because histamine does not produce a strong odor; the fish may smell normal even when histamine levels are dangerously high. (70% fail)
- **** — Reheating the fish to 165°F fails because histamine is heat-stable and remains toxic after cooking. (85% fail)
- **** — Freezing the fish fails because histamine is not destroyed by freezing; it can accumulate during initial temperature abuse and persist in frozen storage. (75% fail)