Food Container Symbols
Every mark on a plastic food container, answered as the question people actually have: can this go in the microwave, the freezer or the dishwasher, and is the plastic meant to be reheated at all.
The number in the triangle is not a recycling promise
The small triangle of chasing arrows with a digit inside is a resin identification code. It names the plastic so a sorting line can separate it. It does not say the container is recyclable where you live, and it does not say the container is safe to heat. Those are separate marks.
| Code | Plastic | Where you meet it | Heat and reuse |
|---|---|---|---|
| 1 | PET or PETE | Water and soda bottles, salad trays | Made for one use. Softens well below oven temperatures. |
| 2 | HDPE | Milk jugs, juice bottles, rigid tubs | Stable and reusable. Microwave only if the pack says so. |
| 3 | PVC or V | Cling films, some bottles and trays | Not a reheating material. |
| 4 | LDPE | Squeeze bottles, bread bags, flexible lids | Low melting point. Fine cold, poor under heat. |
| 5 | PP | Reusable boxes, takeout tubs, most lids | The code most often paired with a microwave-safe mark. |
| 6 | PS | Foam cups, disposable cutlery, takeout trays | Deforms with heat. |
| 7 | Other | Everything else, including polycarbonate and bio-based plastics | Tells you nothing on its own. Read the written marks. |
The marks that answer the real question
- Microwave safe — usually three wavy lines, sometimes inside a box or above a dish. The same lines with a bar through them mean the opposite.
- Dishwasher safe — a plate or glass with water falling on it. A variant showing the item on a rack means top rack only, furthest from the element.
- Freezer safe — a snowflake, sometimes with a temperature beside it.
- Oven safe — an oven outline, or a maximum temperature. Oven safe never implies grill or broiler safe.
- Glass and fork — the food-contact mark. The material may touch food. It says nothing about heating, freezing or washing.
- Temperature range — some makers skip pictures and mold a range such as -20 to 100 into the base. That range is the whole instruction.
What an unmarked container means
No information. Not permission. Unmarked takeout tubs, jars reused from another product and bases scuffed blank by a dishwasher all fall into this group. Treat them as cold storage.
Traps worth knowing
- Lid and base are often different plastics with different ratings. A microwave-safe box can have a lid that is not.
- Molded marks are unpainted and shallow. Tilt the base under a light before deciding there is no mark.
- Microwave safe means the container will not deform or shed material in normal use. It does not mean food heats evenly, and it does not cover oil or sugar syrup, which get far hotter than water.
- Only one mark here exists as real text: the generic recycling symbol ♺ (U+267A). The numbered resin triangle is drawn artwork, not a character, so it cannot be typed or pasted.
For marks printed on the label rather than molded into the container, see food label symbols. For the wider packaging set, see food packaging symbols and food safety symbols.