That depends on the cabinet. The Code sets no maximum per cabinet, but it does set a requirement for the spill sump: it must hold at least the largest container and at least a quarter of everything in the cabinet. In practice, you therefore store at most four times the sump volume, in containers that are each no larger than the sump. A cabinet with a 30-litre sump thus takes up to 120 litres. Also respect the maximum shelf load stated by the manufacturer.
Above certain quantities you must also notify the storage or obtain a permit: see the thresholds by region in our guide. We help you choose the right cabinet size and layout.