Polyester is a synthetic material used in textiles and various consumer goods. Like virtually all manufactured products, polyester does off-gas chemicals, primarily Volatile Organic Compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs). This process is a natural result of how the material is made and finished. Understanding the nature of off-gassing and the specific compounds involved helps consumers make informed decisions about the products they bring into their homes.
Understanding the Process of Off-Gassing
Off-gassing describes the release of airborne chemicals from solid or liquid materials into the surrounding environment. This phenomenon is responsible for the characteristic “new product smell” often noticed with new carpets, furniture, or textiles. The chemicals involved are generally classified as either VOCs or SVOCs, which are organic chemicals that vaporize at room temperature.
Volatile Organic Compounds (VOCs) have a relatively high vapor pressure, meaning they evaporate easily and quickly dissipate into the air. Semi-Volatile Organic Compounds (SVOCs) have a lower vapor pressure, causing them to evaporate more slowly and often adhere to airborne dust particles or surfaces. The rate of off-gassing is typically highest when a product is new, decreasing significantly over the first few weeks or months. However, some SVOCs can continue to be released at lower concentrations for years due to their slow evaporation rate.
Specific Chemical Compounds Released by Polyester
Polyester is chemically known as polyethylene terephthalate (PET). The finished fabric contains residual chemicals from its manufacturing process, including unreacted monomers, catalysts, and chemical finishes. The primary compounds of concern are not the polymer itself, but these residual substances trapped within the final material.
Antimony trioxide is commonly used as a catalyst in PET production and detectable amounts of this metalloid remain embedded in the fibers. Additionally, residual VOCs and SVOCs from manufacturing, such as acetaldehyde and ethylene glycol, can be slowly released from the finished fabric.
Formaldehyde is another common chemical associated with polyester, often introduced during the finishing processes rather than polymerization. It is frequently used for wrinkle resistance, dyeing, and achieving certain textile properties. Dyes and finishing agents can also contain other substances, including aromatic amines and heavy metals, which have the potential to off-gas or leach from the material over time.
Environmental Factors Influencing Chemical Release
The rate at which polyester releases chemical compounds is heavily influenced by environmental conditions. Elevated temperatures are a primary accelerator for off-gassing because heat provides the energy needed for chemical molecules to break free from the material’s structure and vaporize.
High humidity can also increase the migration of certain chemicals from the material’s surface into the air. Exposure to sunlight or ultraviolet (UV) light can cause the polymer structure to degrade, facilitating the release of trapped chemicals. The highest rate of off-gassing usually occurs when the product is brand new and then slows down as the most volatile compounds dissipate.
Reducing Exposure and Health Considerations
Exposure to off-gassing from polyester can be minimized through several practical steps. New polyester textile products, such as clothing or bedding, should be washed multiple times before first use. Washing helps remove residual surface chemicals, including unreacted monomers and excess finishing agents like formaldehyde.
For larger items like carpets or upholstered furniture, airing them out in a well-ventilated space for several days or weeks allows the initial, most intense period of off-gassing to pass. Maintaining moderate indoor temperatures and humidity levels can also help reduce the long-term rate of chemical release.
Low-level exposure to VOCs and SVOCs may result in general symptoms like irritation of the eyes, nose, and throat, headaches, or dizziness in sensitive individuals. Some compounds are linked to more significant health concerns, such as allergic skin reactions or respiratory issues.