Nurdles are small plastic pellets that serve as the foundational material for nearly all plastic products manufactured globally. These pre-production plastic resins are typically lentil-sized (1 to 5 millimeters in diameter). While crucial to the plastic industry, their widespread presence in the environment highlights a significant pollution challenge. This article explores their origins in manufacturing and details how they become environmental contaminants.
The Origin of Nurdles in Manufacturing
Nurdles originate in petrochemical plants or plastic manufacturing facilities, primarily derived from fossil fuels like oil and gas. These pellets are the raw material that the plastics industry molds into a diverse array of finished goods, ranging from everyday items such as plastic bottles and containers to more complex components like car parts. This process transforms raw polymers into uniform pellets.
Monomers, which are small molecular units, undergo polymerization to form long polymer chains, with different types of polymers produced depending on the desired properties of the final product, such as flexibility or durability. The resulting polymer resin then enters an extrusion process. During extrusion, the material is melted and forced through a die, forming continuous strands.
These molten strands are rapidly cooled to solidify them. Once solid, they are cut into uniform pellets by a machine called a pelletizer. The nurdles are further cooled and dried to prevent clumping during storage or transport. This process yields billions of pellets annually, with approximately 27 million tonnes manufactured each year in the United States alone.
How Nurdles Become Environmental Pollutants
Nurdles frequently escape into the environment at multiple stages of the plastic supply chain. Accidental spills during transportation are a major contributor. Nurdles are shipped globally by various means, including container vessels, trains, and trucks, and incidents like damaged containers or train derailments can release billions of pellets. For example, a 2021 incident involving the X-Press Pearl container ship off Sri Lanka resulted in an estimated 70 billion nurdles spilling into the ocean.
Mishandling during loading and unloading at factories, manufacturing sites, and even recycling facilities also accounts for significant losses. Pellets can fall out of rail cars, leak from hoses, or escape due to inadequate packaging or poor operational practices. Chronic terrestrial leaks, often from manufacturing facilities, are considered the largest source of pellet pollution on land. This occurs when pellets are inadvertently washed into drains during factory cleaning or due to a lack of proper containment.
Once released, their small size and lightweight nature make nurdles highly mobile and easily dispersed by wind and water. They can be blown into drains, carried by stormwater runoff into rivers, and eventually flow into oceans, contaminating shorelines and marine environments globally. An estimated 230,000 tonnes of nurdles are thought to enter the oceans annually.