England's Center for Environmental Hazards say plug-in air fresheners produce 'considerable' levels of formaldehyde.
Researchers found particulates from agarwood and sandalwood are more toxic than tobacco smoke.
And scented paraffin candles make ultra-fine soot particles containing acetone, benzene and toluene. Sorta like sucking on a diesel exhaust pipe.
Still feel like filling your trailer-house with the smell of the 60s? Have fun...