Oleic acid (CAS 112-80-1): storage and disposal

Air is what decides how this bottle ages, so the cap matters more than the shelf. An oily liquid that has been opened often picks up oxygen and changes colour, so keep the cap firmly seated and date the bottle on arrival. Store it in a dry, labelled, well organised store at a stable temperature, away from direct light and from the heat of a window ledge or a heater. A bottle that has been used for school practicals is often left with a greasy film around the neck, which should be noted. Separate food grade oils and fatty acids from laboratory stock.

Fresh liquid is pale, so any yellowing or browning is the first sign. Oleic acid slowly takes up oxygen from the air, going darker and developing a rancid smell, and an old, often opened bottle is the likeliest to show it. A sticky or greasy film around the neck, a stuck cap and a stained label are also typical. Other general checks apply: cracked containers, faded labels and an unknown date of receipt. A bottle that has darkened or smells rancid is still a chemical waste to be described accurately, and should be capped, kept upright and listed for collection.

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 We do not publish a drain or general waste route for any chemical.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

It must never be poured into a sink or drain, where an oily liquid coats pipework, and it must not go in a bin or skip. Because it is not normally classified as hazardous, the load is described on a waste transfer note, with an accurate description of what the bottle holds. Waste code 16 05 09 usually fits, and the producer confirms the classification. Note the colour, any smell, the volume left and whether the cap is stuck, since a greasy bottle is awkward to lift. The collector lists it by name and keeps oily liquids upright and separate from solids in the pack.

Usually held as: neat.

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.