Barium carbonate (CAS 513-77-9): storage and disposal

Fine powder is the thing to plan for. Because the classification includes harm on inhalation, a tub that sheds dust when opened is a problem, so keep the lid tight and the container clean on the outside. It is general class stock, so a dry, labelled, well organised store suits it, dated on arrival, away from food grade supplies and clearly separate from the calcium and magnesium carbonates it resembles. Acids dissolve the powder into soluble barium salts, so do not shelve it in or beside the acid store. Where a stock record is kept for barium compounds, it belongs on that list.

The powder is stable, so what happens is mostly about the tub. Caking or clumping points to damp, white dust around the lid shows a poor seal, and a faded label can leave an unknown carbonate with a barium compound's classification and no one aware of it. A missing date of receipt is common in old school stores. Cracked tubs and split bags leak a fine dust, which settles on the shelf below. Stock that has clumped is still barium carbonate and keeps its classification. Set any tub with a worn or doubtful label aside and mark it clearly, rather than returning it to the shelf.

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.

Mistaken identity is the awkward problem here. A tub labelled only as a carbonate in an old store can be barium carbonate, so each one should be read, named and recorded before it goes. It is hazardous waste, collected under 16 05 06* in a lab pack or 16 05 07* outside one. Fine powder escapes from loosely closed tubs, so keep lids on and do not tip contents into another container. It must not go into a sink, a drain, general waste or a skip, and no one should try to treat it first. Record the form and the approximate amount in each tub.

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.