Copper(II) carbonate (CAS 12069-69-1): storage and disposal

Check what the green tub is sitting beside. Basic copper carbonate belongs on a general shelf in a dry, labelled store, dated on arrival, away from food grade supplies and clear of the acid store, because acids attack carbonates. The classification includes harm if inhaled, so a fine powder that rises on opening needs a lid that seats properly and a clean outside. Tubs issued for decomposition practicals should return to the store with the label intact, and any that have been used to hold heated residue should be labelled as such, not shelved as clean stock.

Clean stock is a bright green powder that runs freely. The main finding in school stores is a tub that is no longer clean: green powder streaked with black, which is what remains after heating, shows that used material has gone back into stock. Clumping points to damp, and green dust around the lid points to a loose seal. A faded label and an unknown date of receipt are common. A tub that is mixed green and black is neither fresh carbonate nor pure oxide and should be described as a mixture of unknown proportion, not returned to use.

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 We do not publish a drain or general waste route for any chemical.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 general laboratory pack with compatible chemicals.

Mixed stock is what makes this item awkward. A tub of green powder with black residue is partly copper(II) carbonate and partly something else, and it should be listed as mixed with an honest note of what you know about it. Keep clean stock and used residue in separate containers, each closed. Because it is classified as very toxic to aquatic life, heated residue included, it must not go down a sink or drain, into general waste or into a skip, and nobody should try to treat it first. It is hazardous waste, normally collected under 16 05 06* in a lab pack or 16 05 07* outside one, though the producer classifies the waste.

Usually held as: basic carbonate.

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.