Last year we moved into our new house and within a month I began getting generally weak with extremely weak arms. I had a few episodes of feeling drunk and not even being able to chew. I'm a cyclist and couldn't cycle for most of the year. They tested for everything from MS to motor neurone disease but put it down to a virus. Then I used a nasal spray. My nasal passages swelled up, I became itchy all over and my lips swelled. The same happened with eardrops. The preservative in them is benzalkonium chloride which is in a concentrated form in nearly every household cleaner (from Pine O Clean to spray and wipe type cleaners). I had started using these cleaners when we moved into our new house because the baths etc are plastic these days and they tell us to use spray and wipe instead of Jif. That was when it all started. In retrospect I believe my 'virus' was in fact this chemical. I have now almost completely recovered except for some weakness in my arms.- by email, NSW.