The Indoor Air Quality Association Australia (IAQAA) has developed a set of draft guidelines on the validation of post-cleaning work in buildings where a person infected with COVID-19 was present.
Titled Post Cleaning Validation of Buildings Contaminated with SARS-CoV-2, the IAQAA says the publication is designed to provide information and assurance to workers, those with whom they come in contact, and people returning to a contaminated building.
The authors say the document has been prepared in response to sudden and unprecedented demand across private and public sectors for advice on ensuring that buildings contaminated with SARS-CoV-2 viral particulate are cleaned to a recognised acceptable standard.
The draft guidelines cover a broad range of topics, including:
- The decontamination process
- Treating air in contaminated buildings and the application of air testing for SARS-CoV-2
- Event history documentation
- Visual inspection
- Cleaning quality control
- Testing of surfaces
- Risk assessment
In the visual inspection category, there is a section on post-cleaning inspection pertaining to HVAC systems.
In it, the authors state a need for decontaminating sections of a receiving system in cases where air is extracted from the work location of an infected individual. Examples are provided of a mechanically ventilated building with mixed-mode or recycled air, or in a kitchen or work area with active air extraction.
Citing a study that shows cooler, higher humidity environments can lead to increased coronavirus longevity, the publication says it is important that all filters are fitted correctly and working efficiently within the HVAC system. Return-air and supply-air registers may require cleaning, and ducts should be cleaned, depending on the time since the infection. The virus lasts for up to nine days on stainless steel, and perhaps longer.
The authors recommend replacing return-air path filtration as an additional precaution. This should be considered after leaving it for a suitable period of time to allow active viral loading to drop where this is possible.
Service personnel should be properly trained to manage potential biohazard risks when handling HVAC components and filters. The authors recommend reference to the AIRAH HVAC Hygiene Best Practice Guideline.
The contribution of 11 professionals, the draft document had input from several sectors, including certified occupational hygienists who specialise in contaminated buildings; doctoral authors; several of the country’s leading infection control, biosafety and disinfection experts; experts in HVAC and its decontamination; and the Chair of the Australian Council of the Restoration Industry Association.
The free report is based on scientific evidence available to the authors at the time of publication. Much of the scientific data it makes references to is awaiting printing or pending peer review.
Read the draft guidelines here.