The Vortian 'Splodey System is a special system that is designed to recognize bio-signatures and explode anyone with the pre-programmed bio-signature.
The Vortian 'Splodey System was once installed in prisons on Vort, but they were eventually discontinued, since they had one major flaw: They were unable to detect bio-signatures if the individual was covered with enough matter. Vortian prisoners exploited this design flaw by hiding deep inside outbound garbage receptacles and presumably this is why there are free Vortians across the universe.
For unknown reasons one of these flawed models was somehow acquired by Sizz-Lorr and installed in the doorway of Shloogorgh's Flavor Monster so that if Zim tried to escape the restaurant, he would explode. However, Eric the Blob secretly offered some advice to escape without exploding, and Zim escaped before The Great Foodening.
Facts of Doom[]
It's believed that the Irkens forcibly commissioned the
Inside the Vortian 'Splodey System.
Vortians to make the 'Splodey System when they were in their uneasy alliance. And apparently, once they conquered their planet, the Irkens either didn't know about this flaw or were so arrogant that they believed that the Vortians wouldn't have the backbone to eventually rebel against them and purposely sabotage some of their creations.
Since this model is discontinued, it's quite likely a newer security system was made so that it wouldn't have any weaknesses to be exploited by prisoners.
It's unknown why Sizz-Lorr would install the System if he presumably was aware that it was discontinued. Though it's possible he wasn't aware of it being discontinued, or he didn't think Zim was smart enough to figure out how to escape.
