Food safety of China-imported kitchen utensils

"100% something" can mean "nothing else was intentionally added", while the material might still be contaminated, eg by using raw materials (or auxiliary chemicals that are not considered part of the product) that were neither of food grade purity nor processed to ensure they are. It can also be a rounded up value - 99.6% silicone, 0.4% of Satan's earwax. Actually, it HAS to be since 100% silicone does not come in various fancy colours unless a pigment or dye - which is not made of any silicone - is added.

"Black list" systems like recall systems will only list things known unsafe. Iit is very unlikely that everything else that is not on the list has been comprehensively tested and found known safe. Also, OEM manufacturers and raw material suppliers can change without the brand/order number of the product changing.

What can help is researching (unfortunately, tiresome work) whether any reputable local supplier OEMs the exact same item - an (eg) European importer has some interest in not being in the focus of a product recall, so there is a chance they will have commissioned laboratory tests or taken other steps to make such problems unlikely, or their product might have even been the subject of a published safety test (eg in test magazines). This would speak for the quality of the manufacturer.

If you have to worry about imports from China, you also need to worry about those from Eastern Europe, South Asia, Latin America and South-east Asia.

If you have any misgiving, check with https://www.cpsc.gov/. There you can also check if there was any recall.

Personally, I would take their word for it if its says food-grade otherwise I have too many things to worry about. Unless it does not perform like normal like melting or turning brittle.