Arutz Sheva spoke with Dr. Ben Fox of the Assaf Harofeh-Shamir Medical Center, about the requirement to wear masks in public.

"There are two reasons to wear a mask," Dr. Fox explained. "The first reason is to protect ourselves: If somebody coughs, these droplets are coming towards me, if they get into my nose, I'm probably going to get sick with corona. The other reason is to stop me from infecting other people. Now obviously if we're sick we shouldn't be going out at all. But we know unfortunately that there's quite a large number of people who pick up coronavirus, they're walking around, they don't know they've got it, and innocently spreading it around. And again, that's a place where wearing a mask can be really effective at stopping the spread in the community."

The next question, he said, is what kind of masks people should wear, explaining that there are N95s, for healthcare workers, regular surgical masks, and a variety of homemade fabric masks.

Calling the fabric mask market a "wild west," Dr. Fox held up a disposable surgical mask explaining that "I think these are the way to go."

"The problem with the fabric masks is that we don't really know - there haven't been clear instructions from the Health Ministry on how to make them... There's thousands of different kinds of fabric, different fabrics have different size holes in them between the fibers, we don't how many layers of fabric, and we don't have clear instructions how many masks we need per person and how we need to be cleaning these masks, washing them in the washing machine, at what temperature, do we need to add a capful of bleach each time, just to sterilize - we don't know. We don't know."

Dr. Fox also cited a Chinese paper which noted that during the first SARS epidemic those medical professionals "with high exposure" to the "previous coronavirus" who wore fabric masks were sick "with flu-like symptoms" 13 times more often than those who wore surgical masks.

He also noted several possible explanations for the increase, such as touching the face more often, not washing the masks properly or frequently enough, or being involved in more risky activities, and said that there is no proof that the symptoms were in fact SARS. However, he said, "there's very strong circumstantial evidence that a fabric mask, if you're not really taking care of it properly, might increase the risk to ourselves."

Meanwhile, Israel's Health Ministry issued guidelines for the use of masks, including how to make homemade masks. These guidelines, published on the Health Ministry site, state:

Types of masks suitable for the general population include:

1. Surgeon’s masks – the standard required by hospitals and clinics and are also suitable for the general population

2. Non-medical oral-nasal masks – provides protection, but the degree of protection depends on the mask

3. Multi-layered cloth masks – can provide very good protection, depending on the type of fabric, its thickness, and the number of layers.

The N95 masks protects from transmission as well, but is not required, except when treating severely ill patients in hospitals undergoing respiratory procedures.

Masks with valves – not suitable in the community because the valve emits air with pressure that can cause spraying of droplets and therefor transmission.

Homemade masks:

In the absence of a medical or commercial mask, it is possible to make an oral-nasal improvised mask or make a multi-folded fabric mask with excellent filtering capacity. The mask should be made from two or three layers according to the thickness and quality of the fabric.

To make a fabric mask, it is recommended to choose woven (non-stretch) cotton fabric as tightly woven as possible (density over 200 threads per inch such as a satin or percale fabric) and fold it into 3 layers (or 500 threads per inch at 2 folds). The fabric should be suitable for washing at 70 degrees Celsius so that it may be reused.

The mask must cover the mouth and nose (possible dimensions are a rectangular mask of 14X18 cm). The mask must be sewn on all sides. Rubber bands can be used instead of laces to tighten the mask behind the ears or on the neck.

It is preferable to make several masks for each person, so that they can be changed whenever the mask is wet, dirty, or overused. The used mask should be kept in a clean plastic bag.

The makeshift masks should be washed at a temperature of over 70 degrees Celsius for 30 minutes or more, and may be dried in the sun or a dryer.

The guidelines also urge Israelis to wash their hands after touching a used mask of any type.