Aspirin (CAS 50-78-2): storage and disposal

Tablets arrive in bottles, blister strips or tubs, and the pack they came in is worth keeping because it carries the name and date. In a school prep room, keep any aspirin used for practical work in a dry, labelled cupboard away from the food and drink supplies kept nearby for demonstrations. A pharmacy or clinic holds its stock with other dispensed medicines, dated on arrival. University labs should put reagent powder in a labelled bottle separate from tablets. Keep the stock in a well organised store and avoid moving loose tablets into unmarked containers, since an unlabelled tub is the main reason aspirin ends up needing a full identification before collection.

A vinegar smell on opening is the recognisable sign of age in a damp or warm cupboard: tablets and powder can take up moisture and start to smell faintly of vinegar as acetic acid is released while the compound breaks down. Look for that smell, along with crumbling tablets, a sticky or caked look, discolouration and damp patches on the label. Blister foil that has lifted lets moisture reach the tablets. Any tub with a faded label or no date of receipt should be treated as old stock, whatever the contents look like.

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.

How it is grouped and packed matters more than the volume. Tablets, loose powder and anything that has gone damp are best kept in their own containers, which the collector can then place in compatible groups in approved packaging. The collection supplier confirms whether the particular aspirin stock is regulated as dangerous goods for transport and, if so, the appropriate UN entry. Do not bin it with the school waste, wash it away or try to treat damp stock yourself. For a clinic or pharmacy the human healthcare code 18 01 09 usually fits, while a school or college would be described as a discarded laboratory chemical.

Usually held as: tablets.

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.