Benzene (CAS 71-43-2): storage and disposal

In a school it usually turns up at the back of an old chemical cupboard, often with a worn label and no date. A sound bottle belongs in a ventilated fire-resistant cabinet with spill containment, away from ignition sources, oxidisers, oxidising acids and corrosive stock. If the seal has failed, leave it where it is and ask for advice before anyone carries it through the building. Repeated exposure damages organs and it may cause cancer and genetic defects, so nothing about keeping it near people is routine. It solidifies in a cold store, which is no reason to warm it. University reference standards may be weaker solutions with their own label wording, so go by what the label says. Any refrigerator holding it must be spark-free.

A faded label or staining on the shoulder is usually the first thing seen, because the liquid itself changes very little. Benzene gives few visual signs of age, and an old clear bottle is no weaker or safer than a new one. A white solid in a cold store is freezing, not decay. The sign that matters is a failed seal, which is common on legacy bottles because benzene softens rubber and many plastics. Look for a perished liner, a level lower than expected or a sweet solvent smell in the cupboard, which means vapour is escaping. Check from the outside only. Nobody should open or sniff it, and a bottle in that state should stay put, with the area kept clear, until a specialist has advised.

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 We do not publish a drain or general waste route for any chemical.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 flammable laboratory pack with compatible chemicals.

Leaving it to evaporate in a fume cupboard is forbidden, and it must never go into a sink, a drain, a general waste bin or a skip. Nobody should try to treat it first, or decant it into a fresh bottle because the old label or cap looks poor. Specialist collection is the only route. Name it plainly as benzene when listing it, since a bottle described vaguely as old solvent will not be grouped or planned for correctly. Say whether it is legacy neat liquid or a reference standard, give the size, and describe the seal and label. The code is usually 16 05 06*, or 16 05 08* for a discarded organic chemical outside a lab pack. A consignment note goes with it, or the special waste form in Scotland, so keep your copy on file.

Usually held as: legacy stock, reference standard.

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.