I don't know, but I think UL is the standard approval and should be honored

Any lighting sold in the US Market should Be UL Approved and should have a UL Sticker on it somewhere.

Ikea is a huge company and I think there is no way that they could import their electric products if they didn't comply with the American standards (UL for all the electric tests). When products are coming from abroad they are checked at the American customs. I think you can buy Ikea products with no concern!

Actually, IKEA does not use UL to list and label their lighting products.

comfortairhelp.com/ETL_LISTED_MARK_CLIENTS_UPDATED.pdf

The most common codes/ laws only require that a fixture be listed and labeled to be installed, not necessarily sold. Many states have laws to work around this requirement especially in the case of one-of-a-kind custom fixtures. Try going to an antique store and seeing if there is a UL label on the fixtures they sell.