Nylon is the commercial name for a group of synthetic polymers known as polyamides, valued across industries for their durability, strength, and elasticity. It was originally developed as a replacement for silk, rapidly becoming a common material in textiles like activewear, swimwear, and hosiery, as well as in industrial applications. Because it is a petroleum-based plastic, the material’s widespread use has created a range of environmental challenges spanning its entire lifecycle.
Manufacturing Footprint and Greenhouse Gases
The initial stage of nylon production carries a substantial environmental burden due to its reliance on fossil fuels as a raw material. Manufacturing virgin nylon is highly energy-intensive, consuming about 250 megajoules of energy for every kilogram of fiber produced. This energy requirement is approximately double that of manufacturing polyester fibers, contributing significantly to overall greenhouse gas emissions.
A specific issue arises during the creation of adipic acid, a precursor chemical required for manufacturing Nylon 6,6. The chemical process releases nitrous oxide (\(N_2O\)) as an unwanted byproduct. Nitrous oxide is a potent greenhouse gas, with a global warming potential that is 273 times greater than that of carbon dioxide (\(CO_2\)). If left untreated, \(N_2O\) emissions can reach up to 300 kilograms for every tonne of adipic acid produced. This single manufacturing step is a disproportionate contributor to the material’s overall climate impact, even though abatement technologies exist to significantly reduce these emissions.
Microplastic Shedding During Use
The environmental impact of nylon continues throughout the product’s lifespan, particularly in the form of microplastic pollution from textiles. When nylon clothing is washed in a machine, the friction and agitation cause tiny fibers to break off the fabric. These microscopic fragments, measuring less than 500 micrometers in length, are known as microfibers.
A single laundry cycle can release hundreds of thousands of these microfibers into the wastewater stream. Most conventional wastewater treatment facilities are not equipped to fully filter out these minute particles. As a result, the microfibers flow directly into rivers, lakes, and oceans, becoming a persistent form of pollution in aquatic ecosystems.
Once in the environment, marine life, ranging from small zooplankton to larger organisms, can ingest the microplastic fibers. These synthetic particles can cause physical harm and introduce toxic substances into the food chain. Nylon microfibers are known to attract and concentrate free-floating industrial chemicals, such as mercury and polychlorinated biphenyls (PCBs), making them more toxic when consumed by wildlife.
End-of-Life Permanence
When nylon products are ultimately discarded, the material’s inherent chemical structure prevents it from breaking down naturally. Conventional nylon is non-biodegradable and can persist in landfills and natural environments for hundreds of years. This permanence leads to massive accumulation of waste, which is a major source of physical pollution worldwide.
A particularly problematic form of nylon waste is abandoned, lost, or discarded fishing equipment, commonly referred to as “ghost gear.” Because of its durability, nylon netting and fishing lines can continue to trap and kill marine animals indiscriminately for decades, making it one of the most lethal types of marine plastic debris. Ghost gear is estimated to account for at least 10% of all plastic litter in the ocean, with 500,000 to one million tons abandoned annually. This physical pollution smothers sensitive marine habitats like coral reefs and mangroves.
Sustainable Alternatives and Mitigation
Efforts to reduce nylon’s environmental footprint focus on both reducing its production impact and establishing a circular economy. A significant advancement is the use of chemical recycling, which can depolymerize nylon waste back into its original monomers, creating a material that is chemically identical to virgin nylon. This process allows the material to be reused repeatedly without a loss of quality.
The most recognized example of this circular approach is ECONYL, a regenerated nylon made from pre- and post-consumer waste, including discarded fishing nets and old carpets. Using this recycled content can reduce the global warming impact of the material by up to 90% compared to traditional, oil-derived nylon production. This method also provides an economic incentive to remove polluting ghost gear from the oceans.
Alternative materials are also emerging, such as bio-based nylons like Nylon 11 and Nylon 610, which are manufactured using renewable feedstocks such as castor oil or plant sugars. These bio-polyamides reduce the reliance on crude oil and can avoid the \(N_2O\) emissions associated with conventional adipic acid production. Researchers are developing innovative surface treatments, like special fabric coatings, that can reduce microplastic shedding from nylon textiles by over 90% during washing.