hahaha, this is actually getting pretty funny. i'd add a bottle to the silhoutte dude's hand, because this is totally soemthing u'd do when ur drunk. i like it!!
actually, that might be funnier without the arrow pointing below, it doesn't go as well. I agree, you might want to add some simple shine to the fire extinguisher, or some other details. I like the little silhouette guy though, that's pretty funny.
The information label could be bigger and more central and more detailed also the black nosille should look 3d like the rest of the design. To give it some background maybe it could be mounted on a wall
place it in the lower right corner of the shirt, and maybe give the person and extinguisher different colors so you can tell which is which. funny, though.