I don't pretend to be an expert on the topic.. however.. I have sewn for over a half of a century and I've got fabrics that have been stored in plastic "bins" for as much as 20 years.. some for up to 4 years without being opened. I have had NO problem with foul odors or deterioration. I have gone into fabric shops and been overwhelmed by the smell of formaldehyde used in processing the fabric.. it's used for setting color and in a process for making the fabric "permanent press". I frequently give the "sniff test" to fabrics.. especially the cheap stuff and if I catch a chemical whiff it stays on the shelf. This is one reason I've been a long time "prewasher" of fabrics.