Can I put any glass container in the oven?

No. Borosilicate handles sudden temperature changes better than soda-lime glass, but lids and plastic parts have their own limits. Check the container's rating before oven use.

How long can cooked food sit out before refrigerating?

The FDA says to refrigerate perishables within 2 hours of cooking, and within 1 hour when the room is above 90°F (32°C).

What temperature should leftovers be reheated to?

The FDA safe reheating temperature for leftovers and casseroles is 165°F (74°C). Stir so heat distributes evenly.

40°FFDA refrigerator limit (4°C) or below

0°FFDA freezer limit (−18°C)

165°FFDA safe reheating temperature (74°C)

2 hoursRefrigeration window

Container materials, compared

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Glass, plastic and stainless steel each solve a different problem: glass resists heat and stains, polypropylene is light and microwave-rated, and 18/8 steel is durable and rust-resistant. The choice comes down to heat limits, weight and how the container is washed.

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Independent reference on containers, materials, and food safety limits

FDA limits and material facts

Numbers that matter

2 hoursRefrigeration windowPerishables should go into the fridge within 2 hours of cooking; the window shortens to 1 hour when the room is above 90°F (32°C).

160°FGround meat minimumThe FDA safe minimum internal temperature for ground meat is 160°F (71°C); poultry needs 165°F (74°C).

2–3×Glass-to-plastic weightA glass container of a given volume typically weighs two to three times as much as the same size in plastic.

Material comparison table

Container materials compared on heat, weight and staining
Material	Heat tolerance	Weight vs plastic	Staining	Microwave
Borosilicate glass	Handles sudden temperature changes better than soda-lime glass	2–3× heavier	Resists staining	Yes, if labeled
Soda-lime glass	Lower thermal-shock resistance	2–3× heavier	Resists staining	Yes, if labeled
Polypropylene (code 5)	Commonly rated microwave-safe	Baseline	Can stain	Yes, if labeled
18/8 stainless steel (304)	Durable, no microwave use	Comparable to plastic	Does not stain	No
Silicone lids	Lid-specific limits	Light	Can absorb odors	Check lid rating
Bamboo or wood	Not for high heat or soaking	Light	Can stain	No

Container materials compared on heat, weight and staining

Which material fits which job?

Match the material to the heat, the weight you carry, and how often the food stains.

Borosilicate glass is the most forgiving option for heat: it expands less when heated than ordinary soda-lime glass, so it handles sudden temperature changes better. That makes it a reasonable choice for containers that go from fridge to microwave or oven, though the lid and any plastic parts still have their own limits.

Polypropylene, recycling code 5, is the plastic most commonly rated microwave-safe for food containers. It is light, which matters if the container travels, and it is the usual pick for lunch boxes and batch-prep tubs. It is not the material to use for high-heat roasting.

18/8 stainless steel (grade 304, about 18% chromium and 8% nickel) is the standard rust-resistant food-grade steel. It is durable and does not stain from tomato or turmeric the way plastic can, but it is opaque, so you cannot see contents, and it should not go into a microwave.

Glass: best heat tolerance, heaviest, non-staining
Polypropylene (code 5): lightest, commonly microwave-safe, can stain
18/8 stainless steel: durable, rust-resistant, not microwave-safe

Terms used on this page

Borosilicate glass: A glass that expands less when heated than ordinary soda-lime glass, so it handles sudden temperature changes better.
Polypropylene (code 5): The plastic most commonly rated microwave-safe for food containers, identifiable by recycling code 5.
18/8 stainless steel: Grade 304 steel with about 18% chromium and 8% nickel, the standard rust-resistant food-grade steel.
Thermal shock: Cracking caused by a sudden temperature change, such as a hot container meeting a cold surface.
Safe minimum internal temperature: The FDA target for cooked food: 160°F (71°C) for ground meat and 165°F (74°C) for poultry.

Common questions

Can I put any glass container in the oven?: No. Borosilicate handles sudden temperature changes better than soda-lime glass, but lids and plastic parts have their own limits. Check the container's rating before oven use.
Is plastic always unsafe in the microwave?: No. Polypropylene (recycling code 5) is the plastic most commonly rated microwave-safe for food containers. Check the label on the specific container.
How long can cooked food sit out before refrigerating?: The FDA says to refrigerate perishables within 2 hours of cooking, and within 1 hour when the room is above 90°F (32°C).
What temperature should leftovers be reheated to?: The FDA safe reheating temperature for leftovers and casseroles is 165°F (74°C). Stir so heat distributes evenly.

How this page was assembled

This page compiles FDA time and temperature limits with published material properties for borosilicate glass, polypropylene and 18/8 stainless steel. No prices, brands or vendor claims are included.

Sources

Sources are the FDA food-safety guidance on refrigeration and reheating and standard material specifications for glass, polypropylene and 304 stainless steel.