46 CFR §98.30-12

1. (a)No person may operate a vessel to which this subpart applies unless each portable tank and/or IBC is stowed on an open deck.
2. (b)No person may stow a portable tank and/or IBC—
   1. (1)In the vicinity of another tank that contains a chemically incompatible product; and
   2. (2)Unless all electrical equipment is explosion-proof or intrinsically safe, as defined in §§ 111.105-9 and 111.105-11 of this chapter, in the area of the tank and its associated equipment that is—
      1. (i)Within 10 feet in any horizontal direction; and
      2. (ii)Within 8 feet above the deck.
3. (c)All IBCs must be secured as specified in 49 CFR 176.74.