What somewhat helps is wrapping the potential leakers in sacrificable (or easily washed) sorbents - a sweater, a shirt, a sock…, a low-cost material that will have a chance to hold the stuff in. Wrapping the assembly in a nonpermeable membrane (small or bigger plastic bag…) is another layer of defense. A bag full of liquid WILL leak. A bag full of wet fabric will make much less damage. The sorbent material will also protect the vessel itself against shock and impacts.
It’s all about probability. Lower the chance of the vessel bursting or leaking, lower the range of spreading of the damage to surrounding environment… And, most important, do it in a simple easy way (otherwise you won’t do it the next time because of laziness or time constraints.)
Like if you’d be designing a process plant, you also don’t want a minor mishap in one part cascade out to the whole facility, and you’ll put in buffer zones.
