Composting Toilets
Composting toilets are a type of wastewater treatment system that uses little to no water and generally do not require a connection to a municipal city sewer line or septic system. They provide an enclosed environment to allow the natural aerobic decomposition process.
People buy composting toilets for many reasons. Some may be looking for an alternative system that alleviates or minimizes the need for water to flush the toilet. Others may seek a system that produces a finished compost that can be handled without requiring direct environmental discharge. Whatever your reasons and whatever system you choose, keep a critical point in mind — make sure that the system you select will do what it claims to do.
How can you be sure the composting toilet you purchase will be adequate?
NSF Certified vs. Meets NSF/ANSI Standards
Composting toilets that NSF evaluates by NSF/ANSI Standard 41: Non-Liquid Saturated Treatment Systems must do more than just pass a test. NSF-certified systems are verified to meet six requirements:
- The toilet system can handle the capacity for an extended period, plus occasional overload.
- The toilet system has no offensive odors.
- The composted output has been demonstrated to meet the required bacterial content levels. Advertising, literature, and labeling are not misleading.
- Products undergoing testing are not accessible to the manufacturer.
- Lab test results are confirmed by parallel testing of toilet systems operating in the field.
Look for the NSF Mark
NSF certifies the composting toilet products through a comprehensive evaluation process, assuring they perform as claimed. Look for the NSF mark on the product to ensure that your composting toilet is independently certified to meet strict public health standards for design and performance.
How NSF Can Help You

What’s New with NSF

CELSIUS® Products Earn NSF Certified for Sport® Certification
August 20, 2026CELSIUS® has earned NSF Certified for Sport® certification for select products, including the CELSIUS VIBES line, reinforcing the brand’s commitment to quality, transparency and consumer trust.
Thomas Vyles Honored With 2026 Walter F. Snyder Environmental Health Award
August 19, 2026The award honors Walter F. Snyder, co-founder and first executive director of NSF, and pioneers whose work advances environmental and public health.
NSF Hosts First External Review Panel for ‘NSF/KWTC 555’ with Key Asian Water Authorities
August 3, 2026Joint standard development gains momentum to enhance confidence in Asia’s water industry and advance drinking water safety.
NSF Achieves European Accreditation for Drinking Water Product Certification Ahead of 2027 EU Deadline
July 22, 2026The ISO/IEC 17065 accreditation from BELAC complements NSF’s testing capacity, enabling end-to-end support for EU Drinking Water Directive (DWD) readiness ahead of the January 2027 deadline.