I have personal, eyewitness information on the tear gas situation. This post is a bit delayed, but important.
Many reports have been issued by the protesters that the tear gas used in Tahrir was much stronger than that on January 25th. There are claims that the tear gas is CS, and can irritate skin, eyes, and mucous membranes. CS gas causes skin problems, raises blood pressure, and can eventually lead to cancer, and even severe injury or death.
How's Business, Tear Gas Economy Flourishes in Tahrir Square.
Study Alleges Tear Gas Used on Protesters Potentially Lethal.
Here is what I know, first hand.
I had a guest from America, Don B. He arrived on November 17th and left on November 28th. He went with his tour guide, Waleed, who is an egyptologist and a revolutionary, to Tahrir Square. Unfortunately, they got a little too close to Mohammed Mahmoud street, on November 22d, which was a police/protest battle-zone. They got gassed at close range.
Of course, they had the typical symptoms of stinging eyes and trouble breathing. But there was an additional symptom indicating that there was something really bad in that tear gas. On the parts of his body not covered by clothing, his skin began to be covered by a bad red rash. Over the course of a few days, his skin became inflamed, and even began to ooze a little pus.
We got fairly worried and took him to a pharmacist in Luxor. We explained that he had been tear gassed. The pharmacist prescribed something called triderm which had an antibiotic in it. The skin on my friends face dried up, and eventually peeled off. We were very lucky that we found a knowledgeable pharmacist.
Pretty harrowing evidence that the tear gas used in Tahrir was much stronger than normal.