Ammonium carbonate (CAS 506-87-6): storage and disposal

Chlorates, strong alkalis and nitrite salts are the things to keep it away from. Chlorates and ammonium salts can form unstable ammonium chlorate, and sodium or potassium hydroxide frees ammonia from an ammonium salt, while sodium nitrite is another poor neighbour for any ammonium compound. A school prep room that shelves it with the caustic bottles should move it. Because the salt gives off ammonia as it ages, the tub needs a tight lid, a dry shelf and a space with air movement, and it should be dated on arrival.

Left to itself, ammonium carbonate slowly gives off ammonia and carbon dioxide, so old stock smells strongly of ammonia and the lumps turn from translucent to white and powdery as they lose substance. A tub that has dwindled in level, a lid that has loosened, and a crust around the neck are the usual finds. Damp makes the powder clump. Check also for a faded label, a cracked tub and no date of receipt. A sharp smell on opening is the stock doing what it does, but record it as aged.

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.

Nobody should leave a tub open to let it dwindle, wash it away or neutralise it: no sink, drain, general waste bin or skip is the route, and staff should not try to treat it. Waste code 16 05 06* is the usual entry, with 16 05 07* where it is a discarded inorganic chemical outside a lab pack. It is grouped in a lab pack with compatible solids and kept apart from chlorates, hydroxides and nitrites. Record the container size, how much remains, whether the lid is sound and whether the smell is strong.

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.