What a temperature range is not
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What we publish
A temperature range, on all 176 containers in this group, taking four values from -40 to 120 F up to -100 to 300 F.
What it is
A statement about what the container tolerates. Which is a material and geometry property.
What it is not
A statement that a container is microwave safe, dishwasher safe or oven safe. Those are specific claims and only a manufacturer makes them.
A microwave is not only hot
It heats unevenly and the food gets hotter than the air. A container rated to 240 F can still have a local hot spot above that.
And a dishwasher is hot and wet and chemical
Three stresses at once, where a temperature range addresses one.
So the range rules things out rather than in
A 120 F ceiling settles that a container is not going in a microwave. A 300 F ceiling does not settle that it is.
Which is how to read it
As an elimination tool, the same way the compounding property treats our five-point chemical resistance rating.
And 109 of 176 are eliminated by it
Everything rated to 120 F, which is 62 percent of the shelf.
The 45 at 240 F are the candidates
Not the answers. A candidate for reheating, subject to whatever the manufacturer actually claims.
And the 2 at 300 F are the only both-ends candidates
Rated -100 to 300 F, which spans a freezer and an oven on paper.
Ask the manufacturer before relying on either
Which is the honest end of it, and the same answer the compounding property reaches about chemical compatibility.
And thermal shock is a separate failure again
A range is a steady-state figure. Moving a container from a freezer straight into hot water is a rate problem, and nothing in the field addresses it.
And a range says nothing about how long
A container rated to 240 F is not rated to be held at 240 F indefinitely. Duration is absent from the field entirely.
The field is nevertheless the most complete we publish
176 of 176 on this shelf, which is better coverage than material, neck or liner achieve anywhere.