reusable PPE can reduce waste if PPE is made from materials that can be autoclaved. Increasing access to autoclaves is something that the Fab Lab network may be able to play a role in, with the most promising decentralized technology being stovetop and solar autoclaves. In addition, making reusable PPE from materials that can be autoclaved would also be a key intervention. Would appreciate other's input and feedback in developing this further.
*Current approach to PPE disposal*
Used Covid-19 PPE is most often classified as infectious, which means a disposal method needs to prevent further disease transmission. At present, there are two approved methods for disposal: incineration and autoclaving (Corse et al. 2015):
Incineration destroys the virus with high temperatures. Hazardous waste is often disposed of in this way, and in developed countries, waste incineration plants are used for energy generation (creating some positive environmental value); however, 'lock-in' of waste streams is an issue (i.e. waste is required to supply these plants when alternative pathways such as recycling could be viable and more effective overall from a sustainability standpoint). Also, toxic gases and GHGs are released, although these can be scrubbed (Fletcher 2020).
Autoclaving is the more interesting choice from a circular economy perspective: autoclaves use high temperature and pressure to kill viruses and other pathogens on surgical instruments (common usage) and other PPE (potential). "High temperatures in the autoclave disrupt membranes and denature proteins and nucleic acids in transmissible agents such as spores, bacteria, and viruses. Autoclaves work by creating a vacuum to replace all initial air with steam that directly interacts with the material" (Eurotherm, 2014, cited in Corse et al. 2015). Autoclaves in theory could be used to sterilize reusable PPE.
Challenges with autoclaving:
* Many hospitals do not have autoclaves on-site, relying on third party contractors (Waste360).
* Autoclaves can be expensive, making them prohibitive investments
* Autoclaves come in different sizes, making some models more/less appropriate for different materials. e.g. in the Ebola crisis, large autoclaves were needed to disinfect mattresses of patients
* Autoclaves can only handle the following types of materials: Pyrex or Type I borosilicate glass, polypropylene, polycarbonate, gloves, stainless steel, pipette tips, paper (put inside autoclave bags), and media solutions. They are not compatible with organic solvents, poorly heat resistant plastic such as polystyrene, polyethylene, and metals excluding stainless-steel (Jove 2020).
*Opportunities and associated research questions*
1. Autoclave technology: 'Stovetop' and solar autoclaves have been developed: see attached for a WHO report on solar autoclaves . This could be crucial for developing and remote locations who do not have access to adequate single-use PPE (WHO 2010), and in general enabling more locations to reuse PPE, potentially increasing demand for reusable materials.
* Could Fab Labs make these solar and stovetop autoclaves?
2. Reusable PPE: More research is needed on whether current types of single-use PPE materials can be replaced by reusable PPE materials that are compatible with autoclaves. Attached is the WHO specifications for PPE, and any new/modified materials would I assume need to meet these standards. Needed are gloves, aprons and gowns, surgical masks, respirators and face protectors in the form of glasses, goggles or face shields.
* Could Fab Labs develop reusable PPE made from materials compatible with autoclaves?
*References*
Corse, T. et. al. 2020. Using Ebola as a Lens to Examine Medical Waste Sterilization. https://onlinelibrary.wiley.com/doi/abs/10.1002/wmh3.164
Fletcher, C. 2020. What happens to waste PPE during the coronavirus pandemic? https://theconversation.com/what-happens-to-waste-ppe-during-the-coronavirus-pandemic-137632
Jove Education. 2020. Proper use of autoclaves. https://www.jove.com/science-education/10381/proper-use-of-autoclaves
UK Government. Routine decontamination of reusable non-invasive patient care equipment. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/877533/Routine_decontamination_of_reusable_noninvasive_equipment.pdf
Waste360. 2020. Hospitals Utilize Medical Waste Sterilizers to Reuse PPE. https://www.waste360.com/medical-waste/hospitals-utilize-medical-waste-sterilizers-reuse-ppe
WHO. 2010. Solar Powered Autoclaves. https://www.who.int/medical_devices/poster_a18.pdf
WHO. 2020. Requirements and technical specifications of personal protective equipment (PPE) for the novel coronavirus (2019-ncov) in healthcare settings. https://iris.paho.org/bitstream/handle/10665.2/51906/requirements-%20PPE-coronavirus-eng.pdf?sequence=1&isAllowed=y
Windfeld et al. 2015. Medical waste: a review. https://www.sciencedirect.com/science/article/pii/S0301479715302176?via%3Dihub
**Recyclable**
Julia: Community-based plastics recycling (such as through the Precious Plastics platform) and community-based PPE production. We could look specifically at Polypropylene as it can be used in autoclaves
Nikhil: I've been thinking the same thing, PP is shockingly under recovered (graphic from Jawad A. Bhatti's thesis, attached); there is currently a company, Purecycle, pursuing an industrial project to fix this problem and in the EU there is an organization, Demeto, that has a similar focus. On a smaller scale, one project I found relevant is the attached paper on Recycled Polypropylene Filament. Fab labs tend to gravitate to the reuse of materials and could become good sites to recycle/upcycle material - filament cost can be significant to some people, and the prospect of "free" filament could be a good incentive. There are a number of technical challenges, but, from a medical waste perspective, the first one is probably: can fab labs handle waste safely and sanitarily?
Took some time this weekend to check out our Filabot at A2, and it looks like we might be able to retrofit it for a potential PP recycling use case.
**Biodegradable**
Brainstorming topic: Some bioplastics are antimicrobial, and could be used for textiles. However, it is uncertain whether these would be appropriate barrier materials, and how biodegradability would be managed after end of life.
