What is Sucralose?
Sucralose is an artificial sweetener originally sold under the trade name Splenda, but now also supplied by a variety of manufacturers under various brand names. 
Is Sucralose Safe?
"Don’t believe the manufacturer’s claim that this sweetener is “natural” or “tastes like sugar since it’s made from sugar.” But also don’t believe the Internet conspiracy theories that it’s toxic; it appears to be safe. Used as a tabletop sweetener (Splenda) and in some baked goods, frozen desserts, and diet soft drinks. Unfortunately, it’s often used with acesulfame." 
Please note that even though CSPI consider Sucralose safe they do not consider acesulfame to be safe, which in the above they note that it is often used with Sucralose.
Sucralean Brand Sucralose