Colchicine (CAS 64-86-8): storage and disposal

Oxidisers and acids stay off its shelf, because toxic stock is kept apart from both so that a leak or breakage cannot start a reaction beside it. Root tip squash practicals are the usual reason a school has any, and the leftover bottle often ends up forgotten behind stains and fixatives. It belongs in a locked cabinet with a stock record instead, since a pale powder in a small unmarked vial is easily mistaken for an ordinary stain or salt. Light slowly darkens it, so the original amber bottle should stay closed and out of the sun. Prepared root tip solutions kept in a refrigerator count too: record them, label them clearly and keep them away from anything linked with food.

Start with the bottle: a brittle cap, a label reduced to a handwritten abbreviation, or a date from long before anyone now in post. Good stock is a pale yellow powder or flakes, and exposure to light takes it darker, so a deeper yellow or brown suggests a long spell in poor conditions. That change does not make it any safer to hold. Old working solutions from cytogenetics practicals may have dried to a yellowish film in the vial, and that is worth recording. Tablets give few visible signs of their own, so rely on the blister or carton and the expiry date. Report what you can see without unscrewing anything, because the powder is fatal if swallowed and easily spread.

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 We do not publish a drain or general waste route for any chemical.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

Never tip a leftover root tip solution into a sink or drain, and do not put vials, tablets or contaminated tips in a general waste bin, or try to treat any of it first. Specialist collection is the single route out. A college or university holder would normally see it coded 16 05 06*. Pharmacy stock is a separate matter: being handled as cytotoxic, it would normally fall under 18 01 08*, so tell us plainly that it came from a pharmacy and keep it apart from ordinary out of date medicines. It is worth stating whether you hold pure powder, a made-up solution or tablets, because each is described differently and the small unlabelled vial is usually what slows things down.

Usually held as: solid, tablets.

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.