You first have to determine if it is a:
Fire wall
Fire partition
Fire barrier
What the rating of the wall is. Depending on what it is some can be 20min, 3/4hr, 1-2-3 hour or more. Then you can determine the specific requirements when you penetrate the membrane (one side of the wall only).
For anyone who wants to read the requirements here is some of the information.
SECTION 712
PENETRATIONS
712.3.2 Membrane penetrations. Membrane penetrations
shall comply with Section 712.3.1. Where walls or partitions
are required to have a fire-resistance rating, recessed
fixtures shall be installed such that the required fire resistance
will not be reduced.
Exceptions:
1. Membrane penetrations of maximum two-hour
fire-resistance-rated walls and partitions by steel
electrical boxes that do not exceed 16 square
inches (0.0103 m2) in area, provided the aggregate
area of the openings through the membrane does
not exceed 100 square inches (0.0645 m2) in any
100 square feet (9.29m2) of wall area. The annular
space between the wall membrane and the box
shall not exceed 1/8 inch (3.1 mm). Such boxes on
opposite sides of the wall or partition shall be separated
by one of the following:
1.1. By a horizontal distance of not less than 24
inches (610 mm);
1.2. By a horizontal distance of not less than the
depth of the wall cavity where the wall cavity
is filled with cellulose loose-fill,
rockwool or slag mineral wool insulation;
1.3. By solid fireblocking in accordance with
Section 717.2.1;
1.4. By protecting both outlet boxes with listed
putty pads; or
1.5. By other listed materials and methods.
2. Membrane penetrations by listed electrical boxes
of any material, provided such boxes have been
tested for use in fire-resistance-rated assemblies
and are installed in accordance with the instructions
included in the listing. The annular space
between the wall membrane and the box shall not
exceed 1/8 inch (3.1 mm) unless listed otherwise.
Such boxes on opposite sides of the wall or
partition shall be separated as follows:
2.1. By a horizontal distance of not less than 24
inches (610 mm);
2.2. By solid fireblocking in accordance with
Section 717.2.1;
2.3. By protecting both boxes with listed putty
pads; or
2.4. By other listed materials and methods.
3. The annular space created by the penetration of a
fire sprinkler, provided it is covered by a metal
escutcheon plate.
