Objective To examine occupational differences in workplace exposure to secondhand smoke (SHS) among young adults in California.

Methods Data are taken from the 2014 Bay Area Young Adult Health Survey, a probabilistic multimode cross-sectional household survey of young adults, aged 18–26, in Alameda and San Francisco Counties. Respondents were asked whether they had been exposed to SHS ‘indoors’ or ‘outdoors’ at their workplace in the previous 7 days and also reported their current employment status, industry and occupation. Sociodemographic characteristics and measures of health perception and behaviour were included in the final model.

Results Young adults employed in service (p<0.001), construction and maintenance (p<0.01), and transportation and material moving (p<0.05) sectors were more likely to report workplace SHS exposure while those reporting very good or excellent self-rated health were less likely (p<0.001).

Conclusions Despite California's clean indoor air policy, 33% of young adults in the San Francisco Bay Area still reported workplace SHS exposure in the past week, with those in lower income occupations and working in non-office environments experiencing the greatest exposure. Closing the gaps that exempt certain types of workplaces from the Smoke-Free Workplace Act may be especially beneficial for young adults.