Polyester fabrics emit small amounts of formaldehyde (a carcinogen),
even after many washings. Natural fibres that are labelled "permanent
press" have been chemically treated, usually with a formaldehyde
finish applied so that it is a permanent part of the fiber. Nylon
fabric is also treated with formaldehyde to make it flameproof.
Formaldehyde is a carcinogen. The vapor released from the formaldehyde
can cause respiratory problems, headaches, insomnia (baby can't
sleep?), watery eyes, asthma attacks, etc. Polycotton bed sheets
have a heavy formadehyde finish for durability. This is a concern
because 8 hours a day are spent in bed. If the label says permanent
press, no-iron, crease-resistant, shrinkproof/stretchproof, the
fabric will contain formaldehyde resin.
Chemicals used to make babies' and children's sleepwear flame-retardant are toxic. For example, deca-bromo-diphenyl oxide is a suspected carcinogen and developmental toxicant. Other flame retardant chemicals outgas formaldehyde at levels as high as 500 ppm. (Chronic exposures of just .1 ppm can result in headaches, dizziness, nasal congestion, scratchy eyes and throat, and immune system damage.) Synthetic clothing such as acrylic, nylon, polyester, and vinyl, contains plastics plus formaldehyde finishes. Sources: Healthy Baby, Toxic World, and The Non-Toxic Home and Office