How do you scan for only specific entities?

This is for an exploding barrel code. Any barrel near an exploding one explodes too.

I added a c_scan instruction to the explosion sprite:
Code:
c_scan(my.x,my.pan,vector(150,150,150),SCAN_ENTS | SCAN_LIMIT );


And a scan event for the barrel:

Code:
if (event_type == EVENT_SCAN)
{
wait(-0.15);
set(my,INVISIBLE);
ent_create (expl1_tga, my.x, fire_blast); 
effect(particle_explo, 9, my.x, vector(0, 0, -100));
effect(particle_explosm, 40, my.x, vector(0, 0,0));
ent_create (smoke_tga, my.x, smokeballs);
ent_create (floor_scorch, my.x, floor_burn);
...........


And it works perfectly. The only problem is that when the player walks near the barrels they explode because the player has ENABLE_SCAN applied.

How do you make it so that the barrel only reacts to other explosions and not the player too?

Code:
action oil_barrel()
{
set (my, METAL | POLYGON);
my.emask |= (ENABLE_SHOOT | ENABLE_SCAN );
my.event = oilexplosion_event;
}