Got an email
''Here's what I found out. Gas masks will only be distributed to citizens. In case of a true emergency there will be army tanks driving up and down the street dispensing gas masks to everyone.
The only way to get gas masks if you are not a citizen is to purchase them directly from a manufacturer. They are a bit costly - about 400 shek/each and they have to be picked up from Kriyat Gat or Tel Aviv.
The company website is
www.shalon.co.il and their phone number is 03 695 7191. They were very nice and helpful when I called.
Maybe they will even deliver to Jerusalem if you have enough orders.''