Zinc iodide (CAS 10139-47-6): storage and disposal

The corrosive classification puts this bottle low down, on a resistant tray, in a ventilated corrosive store. It does not belong on the solvent shelf, where a leak could eat into containers and feed a fire, or beside the oxidisers, which can react with corrosive stock and give off heat or fumes. Iodides are also easily oxidised, so a bottle shared with an oxidising shelf is doubly badly placed. Keep light off it as far as a cupboard allows, since an iodide bottle left on a sunny window ledge changes more quickly. Check that the cap seats properly, write the date received on the label, and keep the stock record in step with what is actually on the tray.

Colour is the clue to watch. Iodide salts tend to turn yellow, then brown, as iodine is slowly set free from them by air and light, so a bottle that has gone from white to tan has been standing too long or too bright. The solid also draws moisture, so look for clumping, a damp cake and a wet ring beneath the base. Brown staining on the inside of the cap or on the tray is another sign that iodine vapour or liquid has escaped. A cracked bottle, a perished cap and a label peeled off by damp all need recording. An even white powder in a dry, clean bottle is what normal looks like.

By specialist collection only. It never goes down the drain or into general waste. It is normally packed in a corrosive other laboratory pack with compatible chemicals.

The waste code carries real meaning here. Zinc iodide in a laboratory pack goes under 16 05 06*, and discarded inorganic stock outside a laboratory pack goes under 16 05 07*, so say which one describes your collection. It is a corrosive hazardous waste and the bottle should be collected whole, with the cap taped and the label legible, standing in a tray until the carrier arrives. Never try to dissolve a caked bottle or rinse it out to make it easier to move, and keep it out of drains and bins. Record the brown discolouration or damp if present, and the collector groups the bottle with compatible corrosive stock in a lab pack.

Usually held as: solid.

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.