I have reviewed the Stanford document and based on it, I have opted for the steam method.  Most non-specialized ovens are difficult to control at 70C. Boiling water is easy to control.

Here are the instructions I have written to implement the steam approach:

. Masks must be handled carefully to avoid excessive contamination. Once a mask is removed, suspend it near the top of a large pot with 5-8 cm of water in it. Place the cover on the pot and heat the water to boiling. Reduce the heat to sustain a slow boil and set a timer for 10 minutes (you can extend this to perhaps 12-13 minutes). Keep the lid on the pot during this time. At the end of the steaming interval, remove the respirator and allow it to drip/drain excess water and air dry. Inspect the mask for damage, and if OK, it is ready to reuse.

Until the PPE availability problem is resolved, we will need to take approaches like this, which balance risk versus need and do our best to help the frontline healthcare community.

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