Boar bristles vs nylon bristles
Toothbrush bristles are typically made from either nylon (synthetic nylon-6 or nylon-11) or boar hair (animal-derived keratin fibers). These materials differ in both origin and performance.
Nylon bristles are synthetic fibers designed for durability, flexibility, and consistent manufacturing quality. They maintain their shape well, dry quickly after use, and provide predictable softness levels. However, they are plastics and do not biodegrade under normal environmental conditions.
Boar bristles are made from keratin, a natural protein also found in human hair. They are a non-vegan material and are biodegradable under appropriate environmental conditions. In use, they tend to be less uniform in shape and stiffness and may absorb more moisture, which can lead to slower drying compared to nylon bristles.
If small fragments are accidentally swallowed during normal brushing, neither material is expected to be significantly digested by the human body. Nylon fibers are not broken down by human enzymes, and keratin-based boar bristles are only slowly and incompletely degraded in the digestive tract. In both cases, small particles are generally believed to pass through the gastrointestinal system without being absorbed in a meaningful way, although outcomes may vary depending on particle size and individual conditions.
From a sustainability perspective, the comparison involves trade-offs. Boar bristles avoid synthetic plastics but involve animal sourcing and may have variability in performance, but with a bamboo handle they are biodegradable and compostable. Nylon bristles avoid animal use and provide consistent performance, but remain synthetic materials that persist in the environment. Nylon bristle brushes require the removal of the bristles (either by cutting the handle or pulling out the bristles) before composting.
Nylon-6 vs. Nylon-11
Most conventional toothbrushes and some bamboo brushes use bristles made from nylon-6, a durable synthetic nylon made from fossil fuels. It is widely used because it is strong, flexible, and cost-effective to produce. Some toothbrushes use nylon-11, which is made from castor oil, a renewable plant-based source. While nylon-11 reduces reliance on fossil fuels, both materials are still synthetic nylons and perform similarly in use.
If small particles are accidentally ingested during normal brushing, neither nylon-6 nor nylon-11 is expected to be significantly broken down or digested by the human body. Instead, they are generally believed to pass through the digestive system as inert particles. Current scientific understanding does not show meaningful differences in how the body responds to these materials based on their source.
Like all nylons, both materials are plastics that do not biodegrade under normal environmental conditions and can persist in the environment, gradually breaking down into smaller particles over time.
The environmental impact of each depends on how it is produced, including energy use, agricultural inputs (for nylon-11), and overall supply chain efficiency. While nylon-11 uses a renewable feedstock, this does not automatically mean a lower environmental impact—depending on how it is grown and processed, its carbon footprint can be similar to or in some cases higher than conventional nylon-6. Neither material is impact-free, and both are long-lasting synthetic plastics.
We currently stock bamboo toothbrushes with nylon-6 and boar hair bristles. Despite the differences, both types of brushes reduce plastic waste.