Even when people try to be fragrance (and other chemical) free, they can have 2nd and 3rd hand residues from personal care, cleaning, and laundry products all over them. Air “fresheners” and scented candles are other items that leave residues on everything. It can take weeks to get it out of skin and pores, and longer to get it out of clothing and bedding, all the while re-contaminating the body and anything else that has contact with the fragranced surfaces or air.
Fragrance (and other toxic) chemicals are just all-pervasive now. Unless people are completely fragrance-free and stay out of fragrance filled places, they will have some degree of fragrance saturation in their clothes, skin, and hair. Some of the residues are also impossible to remove no matter how hard one tries, because of chemicals that are designed to penetrate and remain active for long periods of time (think of the laundry commercials where they boast you can smell the fresh scent days later – except some of us can be affected years later, because that’s how permanent those chemicals are).
If people who use those products come to visit, not only can they leave us gasping for air (or worse) during their visit, they can leave chemical residues that will keep off-gassing from the couch and anyplace else they touched for days or weeks to come.
Depending on how severe one’s MCS/ES is,there are different things that can be done.
Seriously "Sensitive" to Pollution 