High indoor VOC levels due to cleaning product overuse, study says

Potentially harmful levels of d-limonene and α-pinene found by UK researchers

UK homes contain potentially harmful levels of volatile organic compounds (VOCs) due to an overuse of cleaning products and a lack of ventilation, a study has found.

A team of researchers from the University of York and King's College London measured concentrations of VOCs in 25 residential UK homes.

Ninety-four percent of homes had levels of monoterpenes, mostly d-limonene or α-pinene. According to the researchers, the two compounds "may well not be significant" in the vast majority of homes at the typical average concentrations found, but they can react with Ozone to form formaldehyde and fine particles which do have adverse health effects.

Moreover, the researchers warn that the effects of long-term exposure, at some of the higher levels found, have not been established. "One might want to take a precautionary approach and reduce emissions in these cases," said one of the study authors, Ally Lewis.

The house with the highest concentration of d-limonene held a mean concentration which was more than 100 times the national average.

D-limonene, a skin sensitiser, was recently the reason for a mandatory recall of cleaning products under Canada's Consumer Product Safety Act (CCPSA). Health Canada said the products contained levels that could pose a danger to human health.

The study also found concentrations of the carcinogens benzene and isoprene, as well as Xylene and Toluene, two skin irritants commonly used in disinfectants and pest control products. But these were "broadly in line with expectations", says Mr Lewis.

Effects of use frequency and ventilation

The level of VOCs found was linked to how frequently the house occupants used cleaning products and fragranced materials, such as air fresheners. In the property with the highest concentrations, it was found residents used nine different cleaning products on more than ten occasions over a week.

The building design also played a role, with modern airtight houses more likely to hold higher levels of the chemicals. Product manufacturers could consider that there has been a trend towards energy-efficient buildings with improved insulation and less ventilation, the study notes.

The researchers say consumers could play an active role in controlling their own exposure to VOCs, by moderating product use or ensuring their home is properly ventilated.

And better public information on fragranced and cleaning products would help avoid a deliberate overuse. Clearer product labelling and advice on ventilation could achieve this, the researchers say.

The paper, Unexpectedly high concentrations of monoterpenes in a study of UK homes, was published in the journal Environmental Science: Processes & Impacts.

The scientists are considering to expand the study to 500 homes, to gather more data.