Formation of indoor nitrous acid (HONO) by light-induced NO sub(2) heterogeneous reactions with white wall paint

Gaseous nitrogen dioxide (NO sub(2)) represents an oxidant that is present in relatively high concentrations in various indoor settings. Remarkably increased NO sub(2) levels up to 1.5 ppm are associated with homes using gas stoves. The heterogeneous reactions of NO sub(2) with adsorbed water on surfaces lead to the generation of nitrous acid (HONO). Here, we present a HONO source induced by heterogeneous reactions of NO sub(2) with selected indoor paint surfaces in the presence of light (300 nm< lambda