Some of what has been published in the UK, specifically, states that the reason disco dust (actually they didn't mention a brand) has been labeled 'non toxic; is because they haven't yet determined definitively whether it is safe to consume or not, so approval (or not) is pending as it is in the States.
This isn't a question of being professional it's a matter of being aware of statutes, recommendations and the laws as they stand in your region/state or country. What is acceptable in your state etc may not be in another.
Bitter almonds is one example. They contain cyanide and some countries and states have banned their sale. The cyanide can be made inert through cooking, but the risk is there. Cyanide is found naturally in apple seeds, apricot kernels and cherry pips - they can pass through the body without effect IF their outer coating hasn't been broken so the body's enzymes can get to it.
Satin ribbon is banned in some States of the US because it's not a food product and isn't passed to be in contact with food.
GM foods are also banned in some countries.
Some food colours are banned in Europe and not in other countries - Red 40, Yellow 5, Yellow 6, Blue 1, Blue 2, Green 3, Orange B, and Red 3 are associated with behavious disorders in children http://www.foodnavigator-usa.com/Business/Pressure-mounts-for-removal-of-artificial-colors
PVC and pthalates are a concern in the US and Europe, but manufacturing processes in Australia and New Zealand don't use pthalates in their products.
If you consider yourself a professional baker or decorator or sell your products to the public, you have a duty of care to keep up to date with food laws and practices for your region/state or country. As you can see from the above examples, not all laws about food transcend all borders.