Labelling a container

Purpose

To make a container state, on its own and without being opened, what is in it, how strong it is, how old it is, what it can do to you, whose it is and which family it belongs to.

When to use it

Before any container is filled. Every one — a stock, a working solution, a decanted concentrate, and a waste container, including the one you expect to empty within the hour.

Before you start

You should already have read reading a safety data sheet, which is where these fields come from, and know why an unlabelled bottle is treated as waste rather than as a puzzle.

On the bench: self-adhesive labels and a pen that survives water; clear tape; the safety data sheet or the supplier’s own label for the material you are about to put in; the chemical inventory or the waste log.

Procedure

1. Write the label before you fill the container. One filled first gets labelled in a minute, and a minute is how long the telephone takes to ring.
2. Write the substance in full, as the source names it, with the hydrate or the form: sodium carbonate, anhydrous, not carbonate and not a trade shorthand.
3. Write the strength unambiguously — % w/v, % w/w, % v/v, mol/L, or the dilution as 1+n. Never a bare percentage.
4. Write the date mixed.
5. Rule a field for the date first opened, and fill it on the day it is first opened. It is a second clock and it runs faster than the first.
6. Copy the hazard wording and the signal word from the sheet for the material you actually used.
7. Add your initials, so that a question has somebody to go to.
8. Add the family in words — DEV, STOP, FIX, WASH or SILVER. A colour code may sit beside it and never instead of it.
9. For a waste container, add four more fields: the source process and dilution; a running volume line to be topped up at every pour; the destination route with the date you checked it; and a telephone number for whoever handles the container after you.
10. Fix the label so that it survives the bench: written on the label, then clear tape over the whole of it.
11. Fill the container. Never one whose shape says drink, and never one whose original label is still on it saying something else.
12. Add the line to the chemical inventory, or to the waste log.

How you know it worked

• Somebody who has never seen the container can say what is in it, how strong, how old, and what it would do to an eye — without opening it.
• The only blank fields are the ones that have not happened yet, and they are present as ruled fields rather than missing.
• The container is not one that has held a drink and does not look like one.
• There is a line for it in the inventory or in the waste log.

If a step fails

Step 2, you cannot state the substance in full. Then you cannot label it and you cannot use it. An unidentified container cannot be used, cannot be stored — you cannot say what it must not stand beside — and cannot be disposed of as anything but an unknown, which is the most expensive waste there is.

Step 3, you know the nominal strength but not the true one. Write both, with the word nominal against the first, and treat the batch as relative rather than absolute: comparable with your own other batches, not with a published formula.

Step 6, you have no sheet for the material you actually used. The material stays closed. That is step 11 of opening the laboratory, and it is the same rule seen from the other end.

Step 8, two families could claim the vessel. It takes the stricter, permanently. Silver-bearing beats every other family, and a vessel does not travel back down the list.

Step 9, you do not yet know the destination route. Leave the route field blank and write in it the date by which you will find out. A blank field with a date on it is a task; a blank field on its own is a container nobody can move.

Step 10, the label will not stick to a cold or wet bottle. Dry it, or write a tag and tie it on. Do not fill an unlabelled container and label it later; later is where this whole procedure goes to die.

You find a container already filled and unlabelled. It is waste. Do not smell it, do not taste anything, and do not pour it into a labelled stream to tidy it away — that destroys the meaning of the label on everything already in that bottle. Give it its own container, date it, write unidentified on it, and settle it before it moves.

What to record

The inventory line for a stock: substance, CAS number, form or hydrate, strength, quantity, the container and its size, the date received, the date opened, the storage group, and the sheet’s version and revision date. The waste log line for a waste container: the date opened, the stream, the container, the date closed, the volume, the route taken and the date you checked that route. The two fields people leave off a waste label are the running volume and the date of the route check, and they are the two that turn a container into a record.