Houseproud women who like to keep their homes clean and fragrant may be at greater risk of breast cancer, research suggests.
Scientists found significant links between the disease and women's use of cleaning products, air fresheners and mould removers.
General use of cleaners doubled the risk of breast cancer in women who used them the most, experts found.
Among the different kinds of products, air fresheners and mould and mildew removers had the strongest association.
In contrast, mothballs, pesticides and insect repellents had little impact on breast cancer risk.
US researchers conducted telephone interviews with 787 women aged 60 to 80 years old with breast cancer and 721 healthy women also in that age range.
The women were asked about their use of cleaning products and split into four groups ranging between high and low users. Cancer rates for the different groups were then compared.
Study leader Dr Julia Brody, from the Silent Spring Institute said: "Women who reported the highest combined cleaning product use had a doubled risk of breast cancer compared to those with the lowest reported use.
"Use of air fresheners and products for mould and mildew control were associated with increased risk."
Air fresheners were found to double breast cancer risk among women in the highest-use group, as did weekly use of mould and mildew-removing agents.
Many pesticides, household cleaners and air fresheners contain ingredients known to trigger breast cancer in animals, said the researchers.
The scientists acknowledged that their results might be swayed by "recall bias" because they depended on answers to questions.
For instance, women who blamed chemical pollutants for their breast cancer might be more likely to report high usage of cleaning products.
However, Dr Brody said it was also true that women with cancer, who thought a lot about the likely cause of their disease, may be more likely to recall their use of cleaners accurately.
Such uncertainty could be avoided by a 'prospective' study which followed the fate of a study group over a period of years.
Dr Caitlin Palframan, policy manager at the charity Breakthrough Breast Cancer, said: "This study doesn't provide convincing evidence that exposure to household cleaning products is linked to breast cancer.
"The research relies on a woman remembering past use of cleaning products. It suggests a woman reports higher use because she thinks there is a link between those products and breast cancer. This could have distorted the results of this study.
"The Breakthrough Generations Study, by following 100,000 women over 40 years, should help provide a clearer explanation of the causes of the disease."