Fluorescein (CAS 2321-07-5): storage and disposal

In school and university prep rooms the stock is powder in a small screw-cap bottle, and in clinic and pharmacy cupboards it is individually wrapped strips. Keep the bottle capped and labelled on a dry shelf and leave strips in their wrappers until the moment of use. It is general stock, so no special cabinet is needed, but the dye is intensely coloured and spilt powder travels on gloves, so a tray under the bottle is worth having. Strips belong with patient-facing supplies rather than with bench chemicals, with the date of receipt written on the box. Keep goggles within reach of the shelf, because the eye is where this powder does its harm.

Good fluorescein powder is a uniform orange-red, dry and free flowing. Clumping, a damp feel or a darker crust inside the neck means moisture has got in, and an orange stain on the cap or shelf shows powder has escaped past the thread. Beyond that the substance gives few visible signs of age, so the container tells you more than the colour does: a faded label, a cracked bottle or no record of when it arrived are reasons enough to list it for collection. For strips, look at the sachet. Torn or damp wrappers, discoloured paper and a printed expiry date that has passed all mean the strips are now waste stock and should not go back into clinical use.

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.

Record what is physically in the container before asking for a collection: loose powder, sodium salt strips or both, how many boxes and whether any are opened. Stock from a prep room or research store is described under the discarded laboratory chemical code 16 05 06*, while a clinic or pharmacy clearing expired strips would normally use 18 01 06*. Strips stay in their boxes and powder bottles stay sealed, so the carrier can group them with other dry laboratory chemicals in a lab pack. Washing residue down a sink or tipping powder into general waste is not an option, and bright staining on the packaging is a reason to bag it separately, not to rinse it.

Usually held as: solid, sodium salt ophthalmic strips.

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.