First, check that there is no reaction taking place producing heat or evolving gasses. So long as the spill is contained it should be possible to deal with it safely – but be aware there are some combinations of acids that can be very dangerous. Both nitric and acetic acid react violently with concentrated mineral acids, possibly creating a much more dangerous solution. With this in mind the spill should be neutralised and adsorbed as quickly as possible. Metal acid cabinets have a very limited lifespan as the corrosive atmosphere eats away at them, regular checks or replacement with plastic ones is advisable.
Charles Harrison is a safety adviser at a UK university