Aluminium sulfate (CAS 10043-01-3): storage and disposal

A technician checking this shelf should look at what the bottle stands on and what closes it. With a classification as possibly corrosive to metals, a bare metal shelf or a metal-capped bottle will eventually show corrosion, so use plastic caps and a tray. Because the eye hazard is serious, keep the jar low and not at head height, particularly in a school prep room with a step stool. Histology stores should file it with other mordant salts and label any stain made from it separately with a date. It needs no special cabinet beyond a dry shelf, and the date received belongs on the label.

Look at the condition of the container and label first. The hydrate crystals can dry out and dust over with a white powder in a warm room, or take up damp and cake into a hard lump in a humid one, so a solid that has fused to the base of the jar has been stored badly. Rust-coloured staining on a metal cap, a corroded thread and a stained shelf all fit the metal-corrosion warning. A label with a faded name or no date is just as important. Aluminium sulfate does not give dramatic signs of age beyond caking and surface change.

By specialist collection only. It never goes down the drain or into general waste. It is normally packed in a non-regulated or low hazard laboratory pack with compatible chemicals.

The code carries the setting. A laboratory pack uses 16 05 06*, discarded inorganic chemical outside a laboratory pack uses 16 05 07*, and a human healthcare setting such as a hospital histology lab uses 18 01 06*. It counts as a hazardous waste on its classification, so staining solutions made from it are described separately from the solid, with volumes. It must never go into a drain or the ordinary bin, however white and plain the crystals look. The transport classification must be confirmed for the specific waste and its form. UN 3264 is an entry for corrosive inorganic acidic liquids, not the solid aluminium sulfate described here. Keep it in a plastic-lined, tightly closed container on a tray, describe any caking, and request a specialist collection.

Usually held as: hydrate.

Part-used bottles and full containers are both fine. Tell us the size and how many, and an estimate is enough for a first price.