[ponygirl]

True story... when I was working as a flight attendant, I was working a breakfast flight on a 737 with the tall food carts in the aft galley. The other gal I was working with didn't check the food carts before plugging them in, assuming they were full of hot meals. It turned out they were those little paper cups of Cheerios and were sitting on top of the warming elements. Catering had placed a packet of Splenda underneath each cup, so the Splenda was heated.

When we were about to go out into the aisle with the cart, I opened the door and realized she had heated the cereal. I lifted one of the cups off the tray and this gross, black, sticky goo was underneath each one. On heating, the Splenda had melted into a tarry black mystery substance.

[smokingfrog]

Research reveals that when sucralose is heated to above 248 °F (120 °C), it may dechlorinate and decompose into compounds that could be harmful enough to risk consumer health.

[higgmeister]

When we were about to go out into the aisle with the cart, I opened the door and realized she had heated the cereal. I lifted one of the cups off the tray and this gross, black, sticky goo was underneath each one. On heating, the Splenda had melted into a tarry black mystery substance.

If you have never read up on Splenda which is a brand name of sucralose, it is made from Sugar.

It is synthesized by the selective chlorination of sucrose in a multistep route that substitutes three specific hydroxyl groups with chlorine atoms.

Here is the Sucrose:

Here is the sucralose

They just break three of the Hydrogen-Oxygen bonds and substitute three chlorine atoms in their place.   Please remember that table salt is just NaCl (Sodium Cloride), so it's not like some strange chemical concoction.   Table salt has a chlorine atom and so does Splenda.

The stuff on the burner was sticky black goo like burned Sugar.

[LesbianThespianGymnasticMidget]

Plain sugar does something similar going through several delicious candy phases followed by phases of caramel before turning to gross black tar and eventually something like charcoal.