Headaches, coughs and other health woes apparently caused by fabric softeners have been rising since 2008, according to a survey by the National Consumer Affairs Center of Japan.
The center suspects the increased popularity of foreign-made fabric softeners, which often smell stronger than Japanese products, may be causing the trend.
Consumer centers and other groups nationwide received 115 requests for consultations from people complaining of health problems between April 2008 and this August, the survey found.
The center said 74 percent of those contacting the groups had not used the fabric softeners themselves but were experiencing problems from products used by neighbors or others.
"I cannot open my window because the smell of laundry from next door is so strong, and causes me to suffer nausea and headaches," one person was quoted as saying.
The center said its research found the amount of the volatile organic compounds responsible for the fragrances is 3.5 to 7 times higher in strong-smelling fabric softeners.
"We want users to be careful as even a smell that is familiar to them can cause discomfort in others," a center official said.