Technically, the FDA does not permit the use of polyester glitter in cosmetics. Polyester glitter is that very familiar plastic style glitter that you often find.
They say that polyester glitters are a new kind of Composite Pigment, to quote them directly:
Since this new kind of pigment isn't specifically on their list of approved color additives, they say that they are not permitted.
Consumers have expressed confusion over this, as it is obvious that there is glitter in all kinds of cosmetics sold currently in the USA. The FDA has indicated that recognizes that the cosmetics industry has been largely unaware of this determination and it is essentially providing the cosmetic industry a grace period during which FDA enforcement is "discretionary". This grace period allows the cosmetics industry to "respond". The FDA has not provided us with any information on how long this grace period has been in effect, nor how long it will be in effect. They simply state the the issue is "active".
Further, they have indicated that while it is active they will allow products into the US that contain certain non-permitted color additives, like glitter, while they continue to review data submitted through the petition process.
An alternative to using polyester glitter is to use other, permitted "glittery" things. These include ingredients such as calcium aluminum borosilicate (glass based materials) and synthetic micas of a large particle size. TKB sells both of these types of glittery materials.