Polyester is a synthetic polymer that is widely used in textiles due to its durability and low cost. The question of its safety for infants is complex. Since infants have thinner skin and less mature organ systems, they may be more susceptible to chemical leachates and physical discomfort compared to adults.
Chemical Residues and Manufacturing Byproducts
The primary health concern related to polyester stems from antimony, a heavy metal used as a catalyst during the polymerization process that creates polyethylene terephthalate (PET). Residual antimony can remain bound within the finished textile. While largely bound, there is a risk of it leaching out, especially when exposed to heat or acidic substances like sweat. Antimony trioxide is classified as a potential carcinogen, and chronic exposure has been linked to skin irritation and stomach issues. Infants are vulnerable because their skin is more permeable and they often engage in hand-to-mouth behaviors, potentially leading to ingestion.
Manufacturing and finishing processes also leave behind other chemical residues. Volatile organic compounds (VOCs) are often used in the dyeing and finishing of polyester fabrics, and these can be emitted into the air through off-gassing. Exposure to VOCs can cause short-term irritation to the eyes and respiratory tract, and some compounds are associated with long-term health issues.
Flammability Requirements and Applied Treatments
A significant chemical concern arises from treatments applied to meet mandatory safety standards. Children’s sleepwear sold in the U.S. in sizes above nine months and up to size 14 must meet strict flammability requirements. These regulations require the fabric to be flame-resistant and self-extinguish if ignited.
To comply, synthetic fabrics like polyester often receive chemical flame retardant (FR) treatments, especially if the garment is not tight-fitting. These treatments may include organophosphate esters (OPEs) or halogenated compounds. Since these compounds are not chemically bound to the textile, they can migrate out into the environment, including household dust. Infants can be exposed through dermal contact, inhalation of dust, or hand-to-mouth ingestion.
Exposure to certain organophosphate flame retardants has been associated with adverse health outcomes in children. Studies have linked prenatal and early life exposure to OPEs with potential neurodevelopmental impacts, preterm birth, and higher birth weight. While these chemicals prevent fire-related injuries, their leaching from textiles presents a significant chemical exposure risk.
Physical Properties and Skin Irritation
Beyond chemical exposure, the physical nature of polyester fabric can pose challenges for infants. Polyester is a hydrophobic material that repels water, making it less breathable than natural fibers. This non-breathable quality traps heat and moisture against the baby’s skin.
Infants have an immature thermoregulation system, making them susceptible to overheating. The trapped heat and perspiration create a warm, moist environment that increases friction between the fabric and the skin. This physical irritation can lead to contact dermatitis, heat rash, and flare-ups of eczema in babies with sensitive skin.
Another concern is polyester’s tendency to shed microscopic plastic fibers. Wearing or washing polyester garments causes the release of microplastics into the air and water. These tiny fibers can be ingested or inhaled by infants, and the long-term health effects are still being researched.
Safer Fabric Alternatives
Parents seeking to minimize chemical and physical risks have several natural and semi-synthetic alternatives to polyester.
Organic cotton is recommended because it is grown without toxic pesticides and is exceptionally soft and breathable. Cotton’s breathability helps regulate the baby’s temperature and prevents the moisture buildup that can lead to rashes.
Merino wool is an excellent option, prized for its natural temperature-regulating and moisture-wicking properties. Unlike traditional wool, merino is fine and soft, making it gentle on sensitive or eczema-prone skin. Hemp and Tencel are also superior alternatives, offering durability, natural UV protection, and softness.
When purchasing alternatives, specific textile certifications provide assurance about chemical safety. The Global Organic Textile Standard (GOTS) certifies that the fabric is made from organic fibers and processed with strict environmental and social criteria. The OEKO-TEX Standard 100 certification tests the final product for a comprehensive list of harmful substances, ensuring the garment is free of chemicals that could pose a risk to human health.