Bottles and tubs

Why there is no glass on this shelf

Updated October 2026

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What the shelf holds Why plastic wins here and loses elsewhere It is handled far more often Weight matters when everything is chilled transport Where glass still belongs Check it behaves cold References

This is the first property in the library whose shelf holds no glass at all, and that is the constraint working rather than a gap in what we stock.

What the shelf holds

A hundred and sixty-five containers between about 237 and 946 ml, of which 120 are PET and 45 are HDPE, with 267 closures. The dominant neck finish is 89-400, which is a wide mouth, and the common formats are single wall jars and packer bottles.

Why plastic wins here and loses elsewhere

The oils property is all glass because an oil sits against its container for a year and the container is part of the preservation system. A dairy product is in the container for days to weeks, so permeation over a long life is not the question. What matters instead is weight, breakage and cold performance, and plastic wins all three.

It is handled far more often

A dairy container is taken out of a fridge and put back daily, carried home in a bag with other shopping, and opened by people in a hurry. Glass in that cycle breaks, and it breaks in a kitchen. The usage pattern decides the material more than the product does.

Weight matters when everything is chilled transport

Refrigerated freight is expensive per unit weight, and a dairy business moves product constantly rather than occasionally. Lighter packaging is a recurring saving on a recurring cost, which is a different calculation from a shelf-stable maker shipping monthly.

Where glass still belongs

A premium bottled milk or a returnable bottle scheme, where the glass is part of the proposition and the economics are built around reuse. That is a deliberate choice carrying a real cost, and it is a different business model rather than a better container.

Check it behaves cold

Plastics stiffen at refrigeration temperature and a closure that seals well on a warm bench may behave differently in a cold room. Verify the seal at the temperature the product actually lives at rather than the one you filled it at.

References

21 CFR 1240.61, Mandatory pasteurization for all milk and milk products in final package form intended for direct human consumption, which prohibits delivering such a product into interstate commerce unless it has been pasteurized or is made from pasteurized dairy ingredients. law.cornell.edu

Written from federal regulation and FDA guidance, not from a laboratory. Pasteurization of milk and milk products in final package form for interstate commerce is a federal requirement, and what your state permits inside its own borders is a separate question. Anything here is a starting point for a conversation with your state department of agriculture, not a determination that you comply.