Unlabelled or undated container

Lifted from reading an SDS and GHS labels and chemical storage and incompatibilities, which established the labelling scheme and the reason an undated container cannot be rescued by a bench test.

What you see

A bottle marked DEV in marker pen. A jar of white powder with a supplier label half peeled off. A storage bottle whose contents are the right colour and about the right volume and whose label says nothing about when it was made. Nothing is visibly wrong with the liquid or the solid, which is the whole difficulty: this is the one defect in the atlas that is read on the outside of the container.

The failure shows itself downstream, as a batch that cannot be explained. A negative comes back thin, and the developer is a suspect, and there is no way to say whether it was mixed last month or last year.

Likely causes

1. The container was filled before the label was written. A bottle filled first gets labelled “in a minute”, and a minute later the session has moved on.
2. A decant. Kodak’s guidance is to store processing chemicals in the containers they were delivered in and not to remove the labels that came on them; a decanted bottle is a bottle whose identity depends entirely on what you wrote on it, and it needs more than the original carried, because now there is a dilution and a date.
3. A label with the family and nothing else. DEV does not say which developer, at what strength, mixed when, what it does to an eye, or who made it.

What is happening: the chemistry and physics

Two clocks run on a container and only one of them is the mixing date. The second starts when the bottle is first opened, because that is when headspace and oxidation begin, and it runs faster.

The reason a date cannot be replaced by an inspection is chemical. Sodium sulfite oxidises to sodium sulfate on the shelf, and Kodak’s 1928 primer states that the sulfate is not easy to detect in desiccated sulfite except by chemical tests. There is no smell, no colour and no change in appearance to read. Mass tells you nothing, because sulfite and sulfate have different molar masses and the jar was never weighed when it was new. The date was the only evidence there ever was, and it was not written down.

Diagnostic questions

• Does the label state the substance in full, not a trade abbreviation?
• Does it state the strength unambiguously, as % w/v, % w/w, % v/v or mol/L, rather than as a bare percentage?
• Does it give the date mixed and the date first opened?
• Does it carry the hazard wording and signal word from the supplier sheet for the material actually used?
• Can you say, from the label alone, what this container must not stand beside?
• Can you say what it is well enough for somebody else to dispose of it lawfully?

Any “no” is the diagnosis.

Corrective action

Retire it. An unlabelled bottle cannot be used, because you cannot state what is in it; cannot be stored, because you cannot state its forbidden neighbours; and cannot be disposed of as anything but an unknown, which is the most expensive waste there is.

Do not attempt to identify it by smell, by colour or by testing a small quantity in a developer. Doubling a quantity to compensate for suspected oxidation substitutes one unknown for another and changes the solvent action of the sulfite as well as its preservative action.

Record the incident in the notebook, with what the bottle was probably for and why it could not be established. A record of retirements is what makes the labelling habit improve.

⚠The container that says drink me

A separate and worse failure sits inside this one. ILFORD’s beginner leaflet states it plainly — do not store chemicals in soft-drink bottles, always label containers clearly, and keep them out of reach of children. A container whose shape says “drink me” must never hold anything but a drink, whatever is written on it, because the label is read after the swallow.

Prevention

Write the label before you fill the bottle, with every field of the course’s scheme — substance in full, concentration stated unambiguously, date mixed, date first opened, hazard wording and signal word, initials, and the family in words. The procedure is labelling a container and it is followed at the bench rather than remembered.

Keep the chemical inventory as one sheet, one line per substance, updated when something arrives or is finished, so that a bottle that has lost its label can at least be matched against a purchase.