When someone uses aerosol sprays such as spray sunscreen, air fresheners, or scented cleaning products, they release volatile organic compounds into the indoor and outdoor air.
When VOCs are exposed to sunlight in the presence of nitrogen oxides (NOx), they participate in a series of chemical reactions that lead to the production of ozone at ground level. VOCs act as reducing agents in the photochemical cycle by reacting with hydroxyl radicals and NO to form peroxy radicals, which oxidize NO to NO₂, further driving ozone formation.
Thus, the use of high-VOC household products adds to the background level of smog-forming substances in the atmosphere, particularly in urban and suburban areas where many people may use similar products frequently. Using cleaning products without scents, that are formulated to contain fewer volatile chemicals would mean fewer compounds evaporate into the atmosphere during use.Opting out of using aerosol sprays altogether, through means such as just sticking to normal sunscreen lotion is also an effective way to reduce personal contributions to photochemical smog.
Without as many VOCs in the air, the reactions that convert NO to NO₂ and sustain ground-level ozone become les productive. This reduces the rate at which ozone forms and contributes to improved air quality, especially during warm, sunny days when photochemical smog is most likely to develop. Using low-VOC products also reduces indoor air pollution, creating a healthier environment for our lungs inside the home.