Potassium chloride (CAS 7447-40-7): storage and disposal

In a school the salt usually sits in an ordinary labelled tub on the general shelf, a few places along from sodium chloride, and that closeness is the main hazard of confusion. Mark the label clearly, date it on arrival and keep food grade supplies apart from laboratory stock. Dry, well organised storage is enough. Not being classified as hazardous on the sources we checked means no special cabinet is needed, but the stock still needs a record. Pharmacy and pathology holders of concentrate ampoules keep them in the arrangement their own medicines procedures set, apart from the bulk laboratory solid, with boxes intact and labels legible.

Sound crystals are white, dry and free flowing. Damp air makes them cake into a hard lump at the base of the tub, and a pot that has been left open may be crusted around the neck. The salt gives few distinctive signs of its own, so the container does most of the work: a faded or lifted label, a cracked tub, mould on a paper label and no date of receipt. In ampoules, look at the glass and the printed label for cracks, leaks and fading. An ampoule with an unreadable label is recorded as unknown and not guessed at.

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.

Packed in a lab pack with compatible low hazard stock, solid potassium chloride is grouped separately from ampoules, since glass and liquid are handled differently from a tub of crystals. Waste code 16 05 09 fits non-hazardous laboratory potassium chloride in a school or university, and 18 01 07 fits non-hazardous laboratory chemicals from human healthcare. Medicinal potassium chloride ampoules are generally covered by pharmaceutical waste code 18 01 09. Even though it is not classified as hazardous on the sources we checked, it does not go into a sink, a drain, a general waste bin or a skip, and staff should not try to treat it first. A waste transfer note covers the movement. Record the form, container size and any ampoule count.

Usually held as: solid, concentrate ampoules.

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.