According to Seattle Times features writer Karen Youso, many chemicals are applied to new garments before they are shipped to your local retailer. Everything from disinfectants, insecticides, anti-mildew sprays, and formaldehyde are applied to new clothing and textiles to ensure their safe arrival to their final retailer. What that means to the consumer is that clothing, stretch jeans for example, can often have a strange odor to it. It is very common because of the dyes and other chemicals used on the denim and cotton fibers, but there are a few things you can try to get rid of odors in stretch jeans.
Wash new stretch jeans before wearing them. Select the "full load" setting on the washing machine. Put the jeans in the washer without other garments. Add 2 cups of vinegar to the wash cycle to reduce mildew odors. After the wash is complete, smell the jeans before placing them in the dryer to see if any odors linger. If the stretch jeans still smell, try Step 2.
Place the stretch jeans alone in the washing machine with fragrance-free detergent. Select the "heavily soiled" wash setting, which allows the jeans to soak for an extended period of time in the detergent. This will remove the odor-causing sprays added to the jeans during manufacturing and shipping. Once the wash is complete, place them in the dryer.
Add baking soda to the dryer by placing 2 tbsp. of baking soda in the bottom of the dryer. Lay the stretch jeans on top of the baking soda. Turn the dryer to the "medium heat" setting, and turn it on. Allow the jeans to fully dry. This may take 20 to 30 minutes.
Spray denim with odor-eliminating sprays to maintain freshness once the stretch jeans are completely dried. Choose fabric-safe sprays from the grocery store. They are located in the laundry detergent aisle.