Dress smell?

If you have the space air out the dress in a safe space away from the any fragrances, or kitchen aromas. I would ask the alterations or dress shop what they do.

Can you air it out in a bedroom for awhile to see if that helps?

Maybe try steaming it, then let it air out by hanging it for a day or two. When you put it back in the garment bag, add a few dryer sheets or some downy unstoppables to the bottom of the bag? Keep us posted!

Thats a great idea! The drier sheets could really help

Does it smell like chemicals or does it just smell like it's been stuffed in a closet? Trying airing it out as much as you can, perhaps even near an open window, to help get the smell out. Also consider storing your dress in a fabric dress bag instead of a plastic one, at least until the smell dissipates.