There is liability issues involved. I believe the government waived them for this crisis.
My bil works in import-export. He told me that they have these construction grade masks that get imported by the hundreds of thousands all the time, with no regulatory approvals required whatsoever.
Last week, they tried getting a shipment through, but the FDA stopped them. They said that since health care workers have started using them for lack of better options, they now fall under FDA regulatory approval. Their hands were tied, and the inspection/verification process could take weeks to months at a minimum. For the last full week they have been working around the clock hand in hand with a contact at the FDA to try to find a loophole so they can get them through already.
Unnecessary extra regulation can cause unnecessary deaths.