It's the time of year when we generally keep our doors and windows shut and maybe light a few scented candles to brighten up the long dark evenings. But is there a potential danger, asks Saleyha Ahsan.
Lots of people use air fresheners and body sprays - almost all of which contain what the ingredients listing coyly describes as "perfume".
All in all, it adds up to quite a fragranced atmosphere - and with little airflow in our increasingly-insulated homes, have you ever wondered what happens to all these perfume chemicals? Well, it seems they could be reacting in the air forming a potentially dangerous cocktail.
http://www.bbc.co.uk/news/magazine-35281338