Oil red O (CAS 1320-06-5): storage and disposal

On a histology bench the oil red O bottle is most often the isopropanol solution, which is flammable and belongs in a ventilated fire-resistant cabinet away from ignition sources and oxidisers. The powder jar is general stock and needs only a dry, labelled shelf. Keep the two in different places and make sure each carries its own label, because the powder jar's wording does not describe the liquid. Where solutions are made up in batches, date each bottle when it is filled and name the solvent. A tray under each bottle holds any drip and shows red at once on white shelving.

Look at the label and condition of the container first, since the red stain gives leaks away. A red crust at the cap of a solution bottle, a lower level than the record and a stained label show solvent has been escaping through the closure. Settling is expected in these solutions: a precipitate forms on standing, seen as sediment or red flecks, and a bottle with heavy deposit should be listed rather than shaken and reused. Powder that is damp or caked has taken in moisture. A missing date, a faded label or an unidentified red bottle is enough to treat it as unknown.

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 We do not publish a drain or general waste route for any chemical.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 non-regulated or low hazard laboratory pack with compatible chemicals.

Never pour solution down a sink or tip powder into the general bin, and do not leave bottles of isopropanol solution near heat while waiting for collection. The powder is not normally classified as hazardous, yet still counts as chemical waste, and a school, university or laboratory store would normally use 16 05 09 for it, with 18 01 07 where a human healthcare service is clearing it. Solutions are described separately with their solvent and size, because a flammable liquid is packed differently from a dry dye jar.

Usually held as: solid.

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.