Smoke-free policies are public-sector regulations and private-sector rules that prohibit smoking in indoor spaces and designated public areas. State and local ordinances establish smoke-free standards for all, or for designated, indoor workplaces, indoor spaces, and outdoor public places. Private-sector smoke-free policies may ban all tobacco use on private property or restrict smoking to designated outdoor locations.

The Community Preventive Services Task Force (CPSTF) recommends smoke-free policies to reduce secondhand smoke exposure and tobacco use on the basis of strong evidence of effectiveness. Evidence is considered strong based on results from studies that showed effectiveness of smoke‑free policies in:

Reducing exposure to secondhand smoke
Reducing the prevalence of tobacco use
Increasing the number of tobacco users who quit
Reducing the initiation of tobacco use among young people
Reducing tobacco-related morbidity and mortality, including acute cardiovascular events
Economic evidence indicates that smoke-free policies can reduce healthcare costs substantially. In addition, the evidence shows smoke-free policies do not have an adverse economic impact on businesses, including bars and restaurants.

Results showed that smoke-free policies were associated with decreases in: secondhand smoke exposure; tobacco use prevalence among young people and adults; and adverse health effects.

Exposure to Secondhand Smoke (search period 2009-2011)
-Self-reported exposures (presence, frequency, or duration): median relative reduction of 50% (Interquartile interval [IQI]: -60% to -43%; 6 studies)
-Secondhand smoke biomarkers in study participants: median relative reduction of 50% (IQI: -79% to -12%; 5 studies)
-Indoor air pollution, as measured by vapor-phase nicotine or respirable suspended particle mass: median relative reduction of 88% (IQI: -95% to ‑81.2%; 11 studies)

Tobacco Use (search period 2009-2011)
-Prevalence of tobacco use: median absolute reduction of 2.7 percentage points (IQI: -4.7 to -1.5 pct pts;11 studies)
-Cessation of tobacco use: median absolute increase of 3.8 percentage points (range: 2 to 17.4 percentage points; 4 studies)
-Tobacco consumption (measured as changes in the amount of tobacco used per person): median absolute reduction of 1.2 cigarettes/day (range: -3.6 to 0 cigarettes/day; 5 studies)

Tobacco Use Among Young People (Adolescents and Young Adults) (search period 2000-2011)
-The prevalence of tobacco use was lower among young people who were exposed to smoke-free policies: median odds ratio [OR] =0.85 (IQI: 0.68 to 0.93; 6 studies).

Health Effects (search period 2000-2011)
-Cardiovascular events: median relative reduction in hospital admissions of 5.1% (IQI: -11.6% to -2.2%; 9 studies)
-Three studies (two additional) reported on changes in cardiovascular mortality, two of which found reductions.
-Asthma morbidity: median relative reduction in hospital admissions of 20.1% (range: -22.0% to -1.3%; 4 studies)
-Two studies reported on self-reported asthma, one of which found a reduction.