Shelf Stable Foods
How long does a tuna packet last once opened?
A sealed tuna packet keeps 18 months in the pantry and 3–4 days in the fridge once torn open — scrape it into a covered tub, because the pouch won’t reseal.
How long does it keep?
| Pantry, from purchase | 18 months |
|---|---|
| Fridge, opened | 3–4 days |
Can it sit out?
Unopened, packet tuna is shelf-stable. Once opened, treat it as perishable — the FSIS 2-hour rule applies.
Perishable food left at room temperature for more than 2 hours should be thrown out — 1 hour if it’s 90°F or hotter (a picnic, a hot car, a summer kitchen).
How to tell if packet tuna has gone bad
- A pouch puffed tight before you’ve opened it
- A sour or ammonia smell as the foil tears
- Fish gone grey and slippery instead of pale and flaked
- Watery liquid pooling around the meat in the tub
When in doubt, throw it out.
Quick answers
How long does a tuna packet last once opened?
A sealed tuna packet keeps 18 months in the pantry and 3–4 days in the fridge once torn open — scrape it into a covered tub, because the pouch won’t reseal.
How long can packet tuna sit out?
Sitting out isn’t the safety question for unopened packet tuna — once opened, the FSIS 2-hour rule applies. Perishable food left at room temperature for more than 2 hours should be thrown out — 1 hour if it’s 90°F or hotter (a picnic, a hot car, a summer kitchen).