Bisphenol A (BPA) is a chemical compound primarily used in manufacturing polycarbonate plastics and epoxy resins, often found in hard plastic containers and can linings. Spandex, also known as elastane or Lycra, is a synthetic fiber composed of long-chain polymers called polyurethane, which gives the material exceptional elasticity. The potential intersection of BPA and spandex in close-fitting garments has become a growing concern regarding health and textile safety. This article investigates the relationship between the chemical structure of spandex and the presence of BPA, exploring the chemical landscape of modern textiles.
The Role of BPA in Synthetic Fibers
BPA is not a fundamental building block of polyurethane, the main component of spandex. Spandex is chemically synthesized using various compounds, but BPA is typically not a primary ingredient in the core fiber itself. The primary structure of spandex is a segmented block copolymer made up of soft, flexible polyether or polyester segments and hard, rigid polyurethane segments, which allows for its characteristic stretch and recovery.
However, the presence of BPA in synthetic textiles like spandex blends has been documented in recent years. This occurrence is attributed to its use as an additive in the broader textile manufacturing process, rather than as a core fiber component. BPA can be utilized as an antioxidant to improve the lifespan and stability of fibers like polyester, which is commonly blended with spandex in activewear.
The chemical may also be applied as an antistatic treatment on spandex fibers or used as a dye-fixing agent for polyester and polyamide textiles. The detection of BPA in garments like socks and sports bras suggests that the chemical migrates from these finishing processes onto the clothing. Testing has shown that some athletic clothing containing spandex and polyester could expose wearers to levels of BPA significantly higher than certain regulatory limits. This discovery has prompted regulatory bodies and certification programs to establish or tighten limits for the chemical in products that have direct skin contact.
Other Chemicals of Concern in Spandex and Textiles
While BPA is a concern, a range of other chemicals present in synthetic textile blends also raise health issues. Spandex is usually blended with materials like polyester or nylon, and these final garments undergo extensive chemical finishing. Many of these finishing chemicals are endocrine disruptors or irritants that are not chemically bound to the fibers and can readily leach out during use.
Common Chemical Additives
A common class of chemicals is phthalates, sometimes used as plasticizers in PVC coatings applied to synthetic fabrics for durability. These compounds, which function as endocrine disruptors, have been detected in clothing made from spandex blends. Azo dyes are responsible for vibrant colors. Certain azo dyes are restricted because they can break down to release aromatic amines, some of which have carcinogenic potential.
Formaldehyde is frequently used in textile finishing to prevent wrinkles and shrinkage, and it is known to cause skin irritation and allergic reactions. Nonylphenol ethoxylates (NPEs) are used as surfactants but can degrade into nonylphenols, which are recognized endocrine disruptors. Residues from compounds used in spandex production, such as toluene diisocyanate (TDI), can also be a source of concern for skin contact and off-gassing of volatile organic compounds (VOCs).
How Chemicals Transfer from Clothing to Skin
Chemicals present in synthetic garments transfer from the fabric to the body through dermal absorption. The skin is a permeable organ, and its ability to absorb these compounds is influenced by several environmental and physiological factors, especially when wearing tight-fitting synthetic clothing like spandex activewear.
Factors Affecting Dermal Absorption
Body heat, often increased during exercise, is a significant factor. Elevated temperatures increase the rate at which chemicals volatilize or move from the fabric matrix to the skin surface, facilitating absorption. Moisture from sweat also acts as a solvent, dissolving non-bound chemicals in the fabric and creating a liquid medium for transfer onto the skin. Since spandex is used in activewear, this sweat-chemical mixture is held in close contact with the skin for extended periods. Friction, caused by movement and the tight fit of the clothing, further enhances the transfer rate by promoting abrasion and potentially compromising the skin barrier. Chemicals not chemically bonded to the fibers leach out onto the skin surface, where they can be absorbed into the bloodstream.
Choosing Safer Clothing Materials and Certifications
Consumers concerned about chemical exposure can prioritize materials and look for independent safety verification. Choosing natural fibers, such as organic cotton, linen, or wool, significantly reduces exposure to many processing chemicals associated with synthetic production. Since spandex is often necessary for stretch, seeking brands that explicitly commit to non-toxic or BPA-free manufacturing processes for their synthetic blends is a practical alternative.
A reliable method for identifying safer textiles is to look for third-party certifications that test for and restrict hazardous substances.
- Oeko-Tex Standard 100: This certification ensures that every component of a textile product, including threads and accessories, has been tested for harmful substances and is safe for human health. The standard specifically includes testing for BPA, with recent updates lowering the permissible limit due to growing concerns about its presence in direct-contact textiles.
- Global Organic Textile Standard (GOTS): GOTS focuses on organic fibers but also requires strict environmental and toxicological criteria for all chemical inputs, such as dyes and auxiliaries. While GOTS covers a broader range of sustainability issues, its chemical restrictions effectively limit the presence of many concerning compounds like formaldehyde and certain azo dyes.
Selecting garments certified by these organizations offers assurance that the clothing has been screened against a comprehensive list of potentially harmful chemicals.