unusual smell

late today my wife and I picked up a smell that smells like the chemical used in giving a woman a permanet. My wife has not had a permanet recently. We cannot find anything in the MH that gives off such a smell. I mentioned that the MH next to us had his propane tank filled this afternoon, but we only smelled the odor late this evening. I do realize that our MH's are close together but this smell does not smell like rotten eggs. I have been told that propane smells somewhat like rotten eggs. Any info would be appreciated if anyone has an idea.
The smell is not coming from the sewer area. I have put the usual sewer chemicals in that tank.
William