Objective To compare air nicotine concentrations according to the smoking policy selected by bars/restaurants in Santiago, Chile before and after the enactment of partial smoking ban legislation in 2007 (establishments could be smoke free, have segregated (mixed) smoking and non-smoking areas, or allow smoking in all areas).

Methods The study measured air nicotine concentrations over 7 days to characterise secondhand smoke exposure in 30 bars/restaurants in 2008. Owner/manager interviews and physical inspections were conducted.

Results Median IQR air nicotine concentrations measured in all venues were 4.38 (0.61–13.62) μg/m³. Air nicotine concentrations were higher in bars (median 7.22, IQR 2.48–15.64 μg/m³) compared to restaurants (1.12, 0.15–9.22 μg/m³). By smoking status, nicotine concentrations were higher in smoking venues (13.46, 5.31–16.87 μg/m³), followed by smoking areas in mixed venues (9.22, 5.09–14.90 μg/m³) and non-smoking areas in mixed venues (0.99, 0.19–1.27 μg/m³). Air nicotine concentrations were markedly lower in smoke-free venues (0.12, 0.11–0.46 μg/m³). After adjustment for differences in volume and ventilation, air nicotine concentrations were 3.2, 35.5 and 56.2 times higher in non-smoking areas in mixed venues, smoking areas in mixed venues and smoking venues, respectively, compared to smoke-free venues.

Conclusions Exposure to secondhand smoke remains high in bars and restaurants in Santiago, Chile. These findings demonstrate that the partial smoking ban legislation enacted in Chile in 2007 provides no protection to employees working in those venues. Enacting a comprehensive smoke-free legislation which protects all people from exposure to secondhand smoke in all public places and workplaces is urgently needed.