Ultrafine particle emission from floor cleaning products.

The new particle formation due to the use of cleaning products containing volatile organic compounds (VOCs) in indoor environments is well documented in the scientific literature. Indeed, the physical-chemical process occurring in particle nucleation due to VOC-ozone reactions was deepened as well as the effect of the main influencing parameters (i.e. temperature, ozone). Nonetheless, proper quantification of the emission under actual meteo-climatic conditions and ozone concentrations is not available. To this end, in the present paper the emission factors of newly-generated ultrafine particles due to the use of different floor cleaning products under actual temperature and relative humidity conditions and ozone concentrations typical of the summer periods were evaluated. Tests in a chamber and in an actual indoor environment were performed measuring continuously particle number concentrations and size distributions during cleaning activities. The tests revealed that a significant particle emission in the nucleation mode was present for half of the products under investigation with emission factors up to 1.1×1011 part. m-2 (8.8×1010 part. mLproduct-1 ), then leading to an overall particle emission comparable to other well-known indoor sources when cleaning wide surfaces.