Good question.

I just remembered this conversation with an American Citizen Services person in Taiwan (from the technically-not-a-US-embassy).

"You know, you kids living down in Yilan ask the funniest questions."
"Oh yeah? Like what?"
"Like if you can use a passport if it's gone moldy."

The hot, humid weather is on its way back to Yilan. And the clothing funk is already back.