Bromocresol green (CAS 76-60-8): storage and disposal

The thing to keep this indicator apart from is the acid and alkali stock it is used with, because a leaking neighbour changes the colour of the solution and stains the powder, and a coloured spill is hard to read in a busy store. Bromocresol green belongs in a closed bottle on a general shelf, with dropper bottles upright in a tray. University stores sometimes hold it in mixed indicator sets alongside others, which makes labelling more important than position. Add the opening date to the solution bottle. Keep it away from food supplies, and do not return unused powder to the jar once it has been out on a bench.

Dye powders like this give few clear signs of age, and staining is the main thing that a technician sees. Blue or yellow marks on the cap, label and shelf mean drips or powder have escaped. The solution may drop in level through a loose cap and leave a crusted ring at the neck. A solution that now looks yellow when it was supplied blue-green, or the opposite, has probably met an acid or an alkali from a contaminated dropper. Powder that has clumped or turned damp shows moisture has entered. Without a date of receipt, there is no way to know how old a bottle really is.

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 We do not publish a drain or general waste route for any chemical.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.

Record the container before asking for a collection: the product name as printed, the form, the strength if stated, the approximate amount and where the bottle was kept. Bromocresol green is not normally classified as hazardous, so a waste transfer note is usually the paperwork that applies, but it stays a chemical waste, usually under 16 05 09, and has to be described accurately. Solution and powder are listed apart. Bottles go into a lab pack with other compatible items. It must never be washed to a sink or drain, and nobody should try to bleach it out.

Usually held as: solid, solution.

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.