Human hair is a compostable material that can be successfully integrated into an organic waste recycling system. Although hair is organic and biodegradable, its unique structure requires specific management techniques to break down effectively in a compost pile. Adding hair to compost diverts waste from landfills and enriches soil, transforming a byproduct into a valuable, slow-releasing soil amendment.
Hair’s Composition and Composting Value
Hair offers value to the composting process primarily because of its chemical makeup. It is composed largely of keratin, a fibrous structural protein rich in nitrogen, which makes up approximately 15% to 20% of the hair’s total weight. This high nitrogen content positions hair as a “green” material, supplying fuel for the microbial populations responsible for decomposition and aiding in pile heating. When balanced with sufficient carbon-rich “brown” materials, the addition of hair helps drive the microbial activity. The resulting compost acts as a sustainable, slow-release source of nitrogen.
Preparing Hair for the Compost Pile
The greatest challenge when composting hair is its tendency to mat and clump, which severely slows decomposition and impedes airflow within the pile. To prevent this, mechanical preparation is necessary before adding the hair to the system. You should avoid adding large bundles of hair all at once, as this creates dense, anaerobic pockets that are difficult for microbes to penetrate.
A fundamental step is to cut or chop longer strands into smaller pieces, which increases the surface area for microbial action. Once prepared, the hair must be thoroughly scattered and mixed throughout the compost heap, never deposited in a single layer. It is beneficial to mix the hair with a significant volume of carbon-rich materials, such as dried leaves, shredded paper, or sawdust, to maintain the correct carbon-to-nitrogen balance.
A proper ratio helps ensure the pile achieves the temperatures needed to break down the tough keratin protein. For home composting, hair should be added in moderation, ideally making up no more than 10% of the total volume of ingredients. Regularly turning the pile after adding hair ensures it is integrated and aerated, preventing the formation of water-repellent mats.
Addressing Common Concerns and Contaminants
Hair will take longer to decompose than most other organic materials in the pile. The dense keratin structure is resistant to degradation, requiring specialized bacteria that produce the enzyme keratinase to break it down. Even in an active, hot compost system, hair may take six to twelve months to fully mineralize and release its nutrients.
A primary concern is the presence of synthetic chemicals from hair treatments. Hair that has been permanently dyed, permed, or chemically straightened may contain substances that could potentially harm the beneficial microorganisms in the compost. While small amounts may be fine, it is recommended to use moderation or avoid adding heavily chemically treated hair to an organic home compost system.
Pet hair is an excellent source of nitrogen but must be screened for contaminants. Fur from pets recently treated with topical flea or tick preventatives should not be composted, as these products are designed to kill small organisms. Avoiding pet feces is also advised for home compost due to the risk of introducing pathogens.