We're going through the same thing at my office as well. About, 75% of the people there smoke and there are a few who like to overdo the perfume to mask the smell. You're right, it just ends up making it worse
We had a woman today have a severe asthma attack after using the restroom where someone had sprayed perfume. She had to leave work and go straight to her doctor's office. She has to use her rescue inhaler almost every day because of it. Finally, management was involved in it. I think tomorrow is when we're having a meeting about it, and hopefully stuff gets resolved.
I feel for ya, and hopefully things can get resolved, but I agree with Rox.. if HR isn't doing anything about it, you need to go higher. There is no excuse for them allowing unsafe work conditions.