Coomassie brilliant blue R-250 (CAS 6104-59-2): storage and disposal

Powder stays in its original jar in a dry, labelled, well organised store, because it is general stock and needs no cabinet. Date it on arrival, and keep the jar apart from the used staining solutions, which tend to collect in bottles beside the gel tank. Those bottles are a separate stock with their own labels, and the powder jar's label does not describe them. A research lab with several users often ends up with two or three half-used jars, so keep one record and consolidate nothing, since combining jars hides their age. A tray under the jar shows blue dust at once.

Sound powder is dry and runs freely behind a clean thread. Blue dust on the shoulder of the jar, a blue-stained label or marks on the shelf below show the closure has failed, and a label stained until unreadable leaves an unknown jar. Lumps, a damp texture or a hard cake mean moisture has entered. This dye gives no specific sign of age, so beyond these checks it gives few visual clues. Rely on the paperwork: no date of receipt, duplicate jars with no record or a stock entry that no longer matches. An unlabelled blue jar is listed unknown and left sealed.

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.

Never put the powder into a sink or general waste, and do not try to treat a stained jar first. Although it is not classified as hazardous on the sources we checked, it stays a chemical waste needing an accurate description. List the powder jars separately from any used gel staining solutions, since the solutions are described by what they contain, usually with solvents, and not by the dye. A university or laboratory store uses 16 05 09 for the powder, and a human healthcare pathology service uses 18 01 07. Keep each jar sealed and upright.

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.