Acesulfame-K is very sweet-tasting sugar substitute that’s completely calorie-free, and like most artificial sweeteners there’s some controversy about their consumption in many different groups, including vegans.
Well there’s been some controversy over whether it’s vegan or not, as there have been people who tested it on animals, but this fails to acknowledge that the reason vegans avoid companies that animal-test is to not support companies that do such awful crimes against animals.
What makes Acesulfame-K Vegan despite it being tested on animals is because the tests on animals were not done by producers of, or manufacturers of the product, nor paid for by those companies. Instead they were done by universities and “researchers” completely on their own, and thus by buying or consuming Acesulfame-K you are not in any way supporting them, and thus it is vegan to consume Acesulfame-K.
So if it's vegan to consume Acesulfame-K is that all I need to worry about?
I would argue no, while it’s vegan it’s a little-studied new artificial sweetener that has in some cases been found to have carcinogenic properties. This being the case while you can eat it as a vegan you should probably avoid having it all the time as there’s no studies saying it’s healthy, so at best it’s neutral, at worst it promotes various diseases, aging, cancer, etc.