Bisphenol A diglycidyl ether (CAS 1675-54-3): storage and disposal

Electron microscopy suites may hold it as one bottle in a resin kit, alongside separately contained hardener and accelerator. Keep the components clearly identified and stored according to the supplier's instructions, away from heat sources such as embedding ovens. Keep those parts in their kit and clearly labelled, because a sticky unmarked bottle is the common find. Sensitisation is the real concern with stock like this: drips on bottle shoulders and on cupboard handles pass to the next person, and allergy can build up over time. A dedicated tray that catches drips helps, as do dated labels on arrival. Cold rooms are less helpful than they appear, since liquid epoxy can turn cloudy or crystallise when chilled. A dry, labelled store keeps it far enough from food supplies and general bench traffic.

Thick, slow-moving resin that barely shifts when the bottle is tilted is usually what you notice first, because the resin thickens as it ages. Dried amber runs down the outside and a cap glued in place are close behind. Neither is a disaster, but a stuck cap should stay stuck: do not force it. Cloudiness or crystals can also appear after cold storage, which is a physical change in the liquid and tells you little about age. A label with no date, or a kit missing its hardener or accelerator, makes it harder to describe. Faint yellowing is common in old resin, and unexpected colour change should be noted. Few other visual signs are reliable.

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.

Specialist collection is how uncured resin leaves the site, and the part-used kit bottle is the usual item. It is tempting to mix leftovers with hardener so that a solid block can be thrown away, but never cure it for that reason, and never put uncured resin in a sink, a drain, a skip or a general waste bin. It is toxic to aquatic life, and resin wastes need accurate description. List resin, hardener and accelerator as separate items with their volumes. Say if you also hold embedded blocks, which are cured and carry a lower hazard, as they need not be grouped with liquids. University labs would normally expect 16 05 06*, and hospital histology labs 18 01 06*.

Usually held as: epoxy embedding resin.

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.