New clothing comes with more than just a new look. Almost all fabric is treated with a cocktail of chemicals that can cause irritation. Clothes are treated with preservatives to prevent mold or mildew during shipping. Formaldehyde resins, dyes and chemicals used in manufacturing can lead to contact dermatitis, eczema outbreaks or respiratory problems from simply breathing the fumes. Some fabrics, like denim, can transfer color to your skin. Happily, laundering or cleaning removes much of the chemical residue.
From:: Wash before wearing.