Barium sulfate (CAS 7727-43-7): storage and disposal

Radiography contrast is the item that gets mislaid. Pharmacy tubs and sachets are held with medicines and follow the pharmacy's own stock control, with expiry dates checked as for any other product. The laboratory powder belongs on a general shelf in a dry, labelled store, dated on arrival and kept away from food grade supplies. Because the powder is very fine and dense, a loose lid lets it spread as white dust on the shelf and over neighbouring bottles. In a school prep room it often sits next to the barium chloride used for sulfate tests, and the two bottles should be clearly different on the label.

The powder itself changes very little. A tub that was fine and free-flowing years ago looks the same now, so the container is the thing to read. White dust around a lid shows a poor seal, clumping means damp has got in, and a faded label or no date of receipt are the usual faults. Contrast products are different because they have printed expiry dates, and sachets or tubs that are split, swollen or past their date should be put aside with their packaging. In a school store the real risk is confusion with barium chloride from a smudged label, not any visible change.

We arrange this by specialist collection. We do not publish a drain or general waste route for any chemical. It is normally packed in a non-regulated or low hazard laboratory pack with compatible chemicals.

Contrast stock changes the description. A hospital pharmacy should check with its responsible pharmacist whether medicines arrangements apply, because out-of-date contrast products are not listed like loose laboratory powder. The usual entry for laboratory powder is 16 05 09, the healthcare chemical entry is 18 01 07 and a licensed medicinal contrast product generally belongs under the medicines entry 18 01 09. None of these is a hazardous waste entry, though the producer classifies the waste. It remains chemical waste and must be described accurately. It must not go into a sink, a drain, general waste or a skip, and nobody should try to treat it first. Give each container's form as powder or contrast product, and keep original packaging on contrast items with the expiry date visible.

Usually held as: solid, radiography contrast.

Tell us the container size and how many you hold. An estimate is enough to start with, and some items cannot be priced until someone has looked at them.