A panel of ventilation experts assembled by OSHA and ACGIH concluded that dilution ventilation, used in virtually all mechanically ventilated buildings, will not control secondhand smoke in the hospitality industry (e.g., restaurants, bars, casinos).
The panelists asserted that a new and unproved technology, displacement ventilation, offered the potential for up to 90% reductions in ETS levels relative to dilution technology.
However, this assertion was not substantiated by any supporting data.
Air cleaning was judged to be somewhere between dilution and displacement ventilation in efficacy, depending on the level of maintenance. The panel also failed to quantify the ETS exposure or risk for workers or patrons either before or after the application of the new technology.
Panelists observed that building ventilation codes are not routinely enforced. They also noted the lack of recognized standards for acceptable ETS exposure as well as the lack of information on typical exposure levels.
However, indoor air quality standards for ETS have been proposed in the scientific literature, and reliable mathematical models exist for predicting pollutant concentrations from indoor smoking. These proposed standards and models permit application of an indoor air quality procedure for determining ventilation rates as set forth in ASHRAE Standard 62.
Using this procedure, it is clear that dilution ventilation, air cleaning, or displacement ventilation technology even under moderate smoking conditions cannot control ETS risk to de minimis levels for workers or patrons in hospitality venues without massively impractical increases in ventilation.
Although there is a scientific consensus that ETS is a known cause of cancers, cardiovascular diseases, and respiratory diseases, although ETS contains 5 regulated hazardous air pollutants, 47 regulated hazardous wastes, 60 known or suspected carcinogens, and more than 100 chemical poisons, the tobacco industry denies the risks of exposure, opposes smoking bans, promotes ventilation as a panacea for ETS control, and works for a return to laissez-faire concerning smoking in the hospitality industry.
Smoking bans remain the only viable control measure to ensure that workers and patrons of the hospitality industry are protected from exposure to the toxic wastes from tobacco combustion.
The full text of this excellent discussion of ventillation and secondhand smoke which is available at: