What goes wrong

The liner failed

Updated October 2026

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Three different attacks Which is why the question has to name the chemistry The failures are slow Permeation without visible damage Which is why 42 of the 191 containers are glass And why 7 phenolic caps are on this shelf Keep retained samples, upright and on the side Seven leaves, three kinds of attack, no general answer References

The archetype says it in one line: chemical resistance is the entire decision.

Three different attacks

A strong base, a strong acid and an organic solvent treat liner materials quite differently, and a liner suited to one can fail against another. There is no general-purpose answer across these seven leaves.

Which is why the question has to name the chemistry

Not whether a liner is chemically resistant, but whether it has been tested against this substance at this concentration at this temperature. The first question gets an optimistic answer and the second a useful one.

The failures are slow

A liner that has swollen, softened or dissolved after months, a cap that no longer seats, a product that has lost solvent through a marginal seal. None of it shows on the filling day.

Permeation without visible damage

A solvent can pass through a wall or a liner with nothing to see, and the symptom is a product that has changed concentration. Weighing a filled, sealed sample at intervals is the cheapest way to detect it.

Which is why 42 of the 191 containers are glass

Glass removes the wall from the argument entirely, leaving the cap, the liner and any fitment. For an aggressive acid or an unusual solvent that narrows the test list usefully.

And why 7 phenolic caps are on this shelf

Thermoset rather than thermoplastic, and historically the choice for aggressive solvents. Seven is a small number and they are worth looking at rather than defaulting to polypropylene.

Keep retained samples, upright and on the side

At one, three and six months, with a weighed control. Every failure on this page is slow and all of them are visible by six months.

Seven leaves, three kinds of attack, no general answer

An acid, a base and a solvent are different problems, so a liner that works across a product range is unlikely to exist. Specify per product rather than looking for one answer.

References

29 CFR 1910.1200(g), Safety data sheets, which requires a sheet for each hazardous chemical produced or imported, in English, with sixteen numbered sections in the order listed and the content of each set out in Appendix D, including section 14 Transport information and section 15 Regulatory information. law.cornell.edu

Written from federal regulation and from measured catalog data, not from a plant floor. Hazard classification is a technical exercise with appendices behind it, and nothing here classifies a chemical or writes a label. The point of these pages is to show which regime applies and what it asks for.