How are chemicals stored in bulk?

When you open up a chemical cabinet in your laboratory, what do you see? More often than not, you see the chemical that you want at that moment, surrounded by others that might be useful, but not at that moment – a litany of chemicals in their packaging. But while the chemicals themselves present a huge variety of experimental possibilities, their containers are more mundane, being mostly a variation on a single theme: glass bottles with a screw top lid, with a smattering of plastic bottles.

Now imagine yourself in the doorway of a chemical warehouse, opening the roll-up door. What would you see? In our warehouse, you’d see a wide variety of containers, but the most obvious one is practically the symbol of our industry – the trusty 55 gallon (or 200 litre) drum. There are so many different varieties of them, but they all seem to come in groups of four, bound in plastic together, and strapped to a wooden or plastic pallet so that a forklift or a pallet jack can lift them easily. Most of these drums are steel, with two or three ‘chimes’ – protruding rings around the drum – that are for strength. The drum is often lined with an epoxy-phenolic or a HDPE coating to protect the steel from corrosion.

For liquids, a typical 200 litre drum has one or two openings, or ‘bungs’. These are typically 10 centimetres or so in diameter, and are removed with a bung wrench, which is definitely not a tool that you would find in a chemical laboratory. It fits into the fittings in the bung and unscrews. It’s amusing to learn all the different kinds of bungs that you can find in the industry – there is always a new one, and it always seems to come on the drum that needs to be opened urgently.