Pet hair is an organic material that can be successfully added to a home composting system. Composting is a natural process that recycles organic matter, turning kitchen scraps and yard waste into a nutrient-rich soil amendment. Pet hair, like all organic matter, will eventually break down, contributing valuable components to the final product. The decomposition process is driven by countless microorganisms that consume the organic material and convert it into stable humus.
Pet Hair as a Composting Ingredient
Pet hair is chemically distinct from most other compost ingredients because it is composed mainly of keratin, a fibrous structural protein. This protein structure, which is also found in horns and feathers, is highly resistant to microbial breakdown, causing hair to decompose slowly. Despite its appearance, pet hair functions as a source of nitrogen within the compost pile, classifying it as a “green” material.
This nitrogen content is beneficial because it helps balance the ratio of carbon to nitrogen (C:N) in the pile. Composting requires a ratio of approximately 30 parts carbon to 1 part nitrogen to fuel the microbes efficiently. Adding hair, which is about 15% nitrogen by volume, helps accelerate the decomposition of high-carbon materials like wood chips or dry leaves. The slow breakdown of the keratin means the nitrogen is released gradually, providing a slow-release nutrient source that enriches the mature compost.
Proper Methods for Integrating Pet Hair
The primary challenge when composting pet hair is its tendency to mat together, forming dense clumps that resist air and moisture penetration. These matted clumps create anaerobic pockets, significantly slowing down the decomposition process. To avoid this, hair should never be added to the pile as a single large mass.
Instead, the hair must be thoroughly mixed or dispersed with other materials. The best technique is to sprinkle small, consistent amounts of hair onto the pile, similar to adding sawdust or coffee grounds. Immediately cover the sprinkled hair with fresh layers of “brown” (carbon-rich) and “green” (nitrogen-rich) materials to prevent it from blowing away.
For larger quantities, such as after a major grooming session, the hair should be mixed with damp materials like shredded paper or food scraps before being incorporated. Burying the hair deep within an active, hot compost pile is recommended, as the elevated temperatures expedite the breakdown of the tough keratin protein. Regular turning or aeration of the pile ensures the hair remains dispersed and exposed to the heat and microbial activity necessary for its eventual conversion into humus.
Essential Composting Limitations and Safety
While natural pet hair is compostable, certain types of hair and related pet materials must be strictly excluded from the pile for safety reasons.
Chemical Treatments
Hair that has been treated with chemical flea or tick preventatives, medicated shampoos, or dyes should not be composted. These chemicals are designed to be toxic and can harm the beneficial microbial ecosystem in the compost, potentially contaminating the final product.
Pet Waste
Pet waste, including dog and cat feces, should also never be added to a home compost pile. The waste from carnivorous animals contains pathogens, such as bacteria like E. coli and parasites like Toxoplasma gondii. These pathogens are not reliably eliminated in the lower temperatures of a typical backyard system and pose a significant health risk if the resulting compost is used in a vegetable garden.
Associated Cleaning Materials
In addition to the hair itself, care must be taken with any associated cleaning materials. Clay-based and silica-based litters are not biodegradable and will not break down in a compost pile, so they should be discarded in the trash. Only wood-based or paper-based litters that are free of chemical additives can be composted, and only after all solid waste has been removed.