Paper towels are a common household item, and their environmental impact, particularly biodegradability, is a frequent concern. Their ability to break down depends on composition and disposal. Understanding what “biodegradable” means and how paper towels are made provides clarity on their fate after use.
Defining Biodegradable
Biodegradable refers to a material’s ability to be broken down by living organisms, such as bacteria and fungi, into natural substances like water, carbon dioxide, and biomass. This process occurs through metabolic or enzymatic action by microorganisms. For a material to be labeled “biodegradable” under certain standards, at least 90 percent should degrade into these components within six months.
The rate of biodegradation depends on environmental conditions, including diverse microorganisms, moisture, temperature, and oxygen levels. It can occur under aerobic (with oxygen) or anaerobic (without oxygen) conditions; aerobic breakdown produces carbon dioxide, while anaerobic breakdown can produce methane. “Biodegradable” does not mean a material will disappear quickly or is necessarily compostable under all circumstances.
Paper Towel Materials and Breakdown
Most paper towels are primarily composed of wood pulp, which consists of cellulose fibers. Cellulose is a natural polymer that is inherently biodegradable, meaning microorganisms can break down the base material. However, manufacturing often includes additives that influence how readily a paper towel biodegrades.
A common additive is a wet-strength agent, which helps the paper towel maintain integrity when wet. While crucial for performance, these agents can increase the “lag phase,” the time before biodegradation begins, by strengthening fiber bonds. Despite this initial delay, the paper material’s ultimate biodegradability often remains intact.
Paper towels may also contain dyes, inks, synthetic fibers for strength and absorbability, or lotions and fragrances. Some water-based inks are biodegradable, but others can hinder breakdown or introduce undesirable substances. Unbleached and undyed paper towels are environmentally preferred. Both virgin and recycled fiber paper towels are generally biodegradable, with recycled options utilizing post-consumer waste.
Disposal Considerations
The biodegradability of paper towels heavily depends on the disposal environment. While their cellulose base allows them to break down, disposal conditions dictate the rate and extent.
In a home compost pile or commercial composting facility, with oxygen, moisture, and active microorganisms, paper towels can break down effectively. Composting returns organic matter to the soil and reduces landfill methane emissions. However, home compost breakdown may be slower than in an optimized industrial setting.
When paper towels are sent to a landfill, their decomposition is significantly hindered. Modern landfills are often anaerobic, lacking oxygen, which slows or prevents natural breakdown. In these oxygen-deprived environments, biodegradable materials can produce methane, a potent greenhouse gas. Paper towels used to clean chemicals, grease, oils, or bodily fluids should not be composted, as contaminants can harm beneficial microorganisms or introduce toxins.