Independent testing by SGS confirmed that the Green Drain GD3 blocks more than 99.9% of aerosolized viral pathogens from passing through the drain opening. Tested using MS2 bacteriophage, the internationally recognized surrogate for influenza, norovirus, and SARS-CoV-2.
Floor drains connected to building sewer systems can act as pathways for airborne pathogens. When trap seals dry out or fail, contaminated air from the sewer system can rise through the drain opening and enter occupied spaces. This is not a theoretical concern. Published research has documented drain-to-air pathogen transmission in hospitals, commercial kitchens, and multi-story buildings.
The SGS viral aerosol retention test measured whether Green Drain physically blocks this transmission pathway. Using MS2 bacteriophage (ATCC 15597-B1) as a standardized viral surrogate, the test aerosolized virus particles and measured how many passed through a drain pipe with and without a Green Drain GD3 installed. The result: the GD3 reduced viral aerosol transmission to below detection limits in all three test rounds.
MS2 bacteriophage is the standard test organism recognized by the U.S. EPA, CDC, and WHO for evaluating viral filtration and barrier performance. At approximately 27 nm in diameter, MS2 is similar in size to influenza and SARS-CoV-2. Critically, MS2 is a non-enveloped RNA virus, making it more resistant and harder to block than most real-world respiratory viruses (which tend to be enveloped and more fragile). If a barrier device stops MS2, it will stop the pathogens that cause actual concern in building environments.
The SGS pathogen control test (Report QDF25-0049810-01) was conducted at SGS-CSTC Standards Technical Services in Qingdao, China, an ISO/IEC 17025:2017 accredited laboratory (CNAS Registration L0604). Testing was performed between June 17 and June 23, 2025.
The test setup used a PVC pipe with a 75mm inner diameter, matching the GD3 model. Two configurations were tested side by side. In the test group, the pipe was sealed at the top with a sealing cap and the GD3 trap seal was installed at the bottom. In the control group, the pipe was sealed at the top but left open at the bottom with no trap seal. Both pipes were placed in separate 1 cubic meter air chambers.
MS2 bacteriophage (ATCC 15597-B1) was aerosolized and sprayed into each chamber. A small fan blew air toward the bottom of each pipe, simulating the positive pressure that occurs in building sewer systems (sewer gas pushing upward through drain openings). Each exposure period lasted 10 minutes.
After exposure, the outer surfaces of each pipe were disinfected and the pipes were transferred to a biosafety cabinet. The internal gas collected inside each pipe was then tested for MS2 bacteriophage content using plaque-forming unit (PFU) assay, which counts the number of viable virus particles present.
The results were unambiguous. In round one, the control pipe contained 72,500 PFU while the test pipe with the GD3 measured below 5 PFU. In round two, the control measured 62,000 PFU against below 5 PFU with the GD3. In round three, the control measured 18,000 PFU against below 5 PFU. Across all three rounds, the GD3 achieved greater than 99.9% viral aerosol retention.
The SGS viral aerosol retention data is most relevant in environments where airborne pathogen transmission through drain systems poses a direct risk to occupant health or regulatory compliance:
Hospital floor drains are documented vectors for pathogen transmission. Published studies have linked drain systems to outbreaks of carbapenem-resistant organisms (CROs), MRSA, and other healthcare-associated infections. A device that blocks greater than 99.9% of viral aerosols through the drain opening is directly relevant to infection control programs and HAI reduction strategies.
In food processing and commercial kitchens, facilities operating under HACCP protocols need to control biological hazards at every point in the production environment. Floor drains that can transmit airborne pathogens compromise the entire food safety system. This test data supports Green Drain's HACCP International endorsement with measurable, independently verified performance.
Building owners and facility managers are increasingly concerned about airborne pathogen transmission through building systems, particularly following the COVID-19 pandemic. This test provides quantified evidence that floor drains protected by Green Drain are not a transmission pathway. For specifiers, this is a differentiator: most waterless trap seal competitors do not have published viral aerosol test data from an accredited laboratory.
Download the full SGS test report (QDF25-0049810-01) documenting greater than 99.9% viral aerosol retention, along with the laboratory's ISO/IEC 17025 accreditation certificate.
Greater than 99.9%. In all three test rounds conducted by SGS, the Green Drain GD3 reduced viral aerosol transmission to below the detection threshold (less than 5 PFU), compared to control group readings of 18,000 to 72,500 PFU without a trap seal installed.
MS2 bacteriophage (ATCC 15597-B1) is the internationally recognized surrogate for testing viral pathogen transmission. It is used by the U.S. EPA, CDC, and WHO because it is similar in size to influenza and SARS-CoV-2 (approximately 27 nm diameter), is non-enveloped (making it harder to block than most human respiratory viruses), and is safe to handle in a laboratory (Biosafety Level 1). If a barrier device blocks MS2, it will block the pathogens that cause actual concern.
The test was conducted by SGS-CSTC Standards Technical Services (Qingdao) Co., Ltd., an ISO/IEC 17025:2017 accredited laboratory (CNAS Registration L0604). The lab's CNAS accreditation is backed by ILAC MRA signatory status, meaning test results are internationally recognized across member countries.
All 8 Green Drain models are covered. Testing was performed using the GD3 (3-inch) as the representative model, installed in a PVC pipe with a 75mm inner diameter in a 1 cubic meter air chamber. Because all models use the same silicone membrane sealing mechanism, the pathogen blocking performance applies across the full product line.
Yes. Hospital and building floor drains have been documented as vectors for pathogen transmission. Published studies have linked drain systems to outbreaks of carbapenem-resistant organisms, MRSA, and other healthcare-associated infections. The SGS test demonstrates that Green Drain blocks greater than 99.9% of viral aerosols from passing through the drain opening.
Download the SGS report directly, or contact us for specification language, infection control documentation, or project-specific technical support.