question: Hi, my friend mixed harpic bleach with normal bleach in a bucket as we were cleaning our flat about 3 hours ago, after mixing the bleach there was an instant extremely strong smell that made us cough for a while, I then emptied the bleach down the sink and we stayed in the room for about 3 hours without realising it is dangerous. I have a very strong burning sensation in my nose and am extremely tired with a headache, and my friend just has a pain in her chest when she breathes deeply. Is there anything to worry about?