ACHRNEWS

A Smoldering Problem

March 11, 2004
ANAHEIM, Calif. - When it comes to cleaning air that contains environmental tobacco smoke (ETS), there's nothing easy about it. Even discussing the issue can pose difficulties.

For instance, there was a seminar titled "Standard 62's Comfort-Only Approach to Smoking Spaces" at the 2004 Winter Meeting of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). The standard addresses comfort considerations in smoking spaces, but not health. Does that do anybody any good?

The real issue seemed to be whether or not you can protect yourself if the building owner decides to offer a smoking environment.

"Can ventilation achieve comfort?" asked moderator Larry Schoen of Schoen Engineering, Columbia, Md. He also announced that the Standard 62 ("Ventilation for Acceptable Indoor Air Quality") committee removed an appendix on comfort ventilation. It will be included in a design guide.

The addenda are at the heart of the problem. First the smoking space information was re-moved from the standard and stuck in addendum 62o. The addendum contains an appendix that describes a method to achieve comfort, but not any health goals, in smoking spaces.

Now the appendix information is being removed from the addenda and will be included in a design guide. Sadly, moving it will not make the problem of dealing with cigarette smoke go away.

This seminar explored the limitations of the new method in reaching this comfort goal and the remaining health risks that are expected when the addendum is used. It also detailed ASHRAE's response to the dilemma posed by the unavoidable health risks versus the desire to get good information out to the engineering community and the public.

How To Comply

Dennis Stanke is a staff applications engineer for Trane, La Crosse, Wis. He answered his own question, "Can a System with ETS Comply with 62-2001?" You can comply with the standard, logically enough, by following the standard's recommendations, he said. Whether or not the air quality will be good seems debatable, especially within the smoking space itself.

According to Stanke, here is what you need to do to comply with the standard:

  • Assess regional outdoor air quality; survey the local air quality.

  • Meet the minimum requirement for natural ventilation, and provide a balanced ventilation system.

  • Operate exhaust ducts with harmful contaminants at negative pressure. Meet minimum requirements.

  • Use controls to ensure proper ventilation under all conditions.

  • Use materials that resist microbial growth and environmental damage. Design for the local capture of contaminants. For particulate matter removal, apply MERV 6 filtration upstream of wet surfaces. Filter outdoor air using MERV 6 filters in applicable geographic regions. Don't operate the building without filters.

  • Make sure there is sufficient combustion air for combustion appliances.

  • Limit relative humidity to 65 percent or less. Make sure systems have functional drain pans and other means of condensate removal. Select the coils and heat exchanger to prevent moisture carryover. Insulate cold pipes to prevent condensation formation.

  • Identify sources of contaminants in order to deal with them effectively.

  • In structures where "dirty" and "clean" zones share the same building, take necessary steps to keep the air from recirculating from the dirty space into the clean. For instance, practice appropriate garage ventilation precautions. Separate ETS from non-ETS areas, avoid recirculation, and post ETS warning signs. Use the ventilation rate procedure or IAQ procedure to find airflow rates.

    If there are smoking areas, there must be ventilation at a higher rate than nonsmoking areas. You must not recirculate between the two areas. How much more ventilation is needed? Stanke said the standard does not specify the amount.

    Likewise, the standard does not include information on what may constitute an acceptable concentration of ETS. It does specify that the designer sets a target limit and site a "cognizant" authority. "It may be difficult to find one," Stanke said. "You need somebody who has expertise and jurisdiction, or authoritative organization."

  • Develop a building O&M (operations and maintenance) manual.

    According to Stanke, if smoking is permitted throughout the building, the system must meet all requirements in all sections.

    In a mixed-area building, the system must meet all requirements, with the additional requirement that the smoking space cannot return air to the nonsmoking space.

    What the standard advises is the design and maintenance of a building system with possibly a higher degree of filtration, and higher-than-normal ventilation air change rates. "We don't know the resulting outcome in terms of health or comfort due to increased ventilation," said Stanke. "It will comply with the standard.

    "Some people say that you can't comply with Standard 62," he said. "You can if you meet all the requirements. However, you can meet all the requirements and still not do it" - achieve good IAQ, that is.

    Big Health Risks

    James L. Repace of Repace Associates Inc., Bowie, Md., is a health physicist and an expert witness on secondhand smoke. He took issue, first of all, with the idea that there is no cognizant authority on ETS.

    "I'm going to be the cognizant authority for the purpose of this talk," he said. Throughout his presentation, he cited statistics from the National Cancer Institute, NIOSH, U.S. EPA, California EPA, Surgeon General's Office, and the National Toxicology program - "all cognizant experts," he said. "They report 60,000 deaths per year due to secondhand smoke."

    He started with a sobering figure. According to 1998 data, there are 48 million smokers in the United States who die from the effects of smoking at a rate of 430,000 per year.

    The ASHRAE guidelines, he said, suggest that the perception of odor, nonrecirculation, and other recommendations can sufficiently address ETS. This, he said, is not so.

    Measuring The Problem In The Field

    One published study looked at ETS at three separate pubs - one each in Toronto, Wilmington, Del., and Boston. The researchers went with measuring devices and a time stamp.

    The Black Dog Pub in Toronto, Repace said, is an ETS "poster child" for the Canadian hospitality industry. The building allows smoking, and its mechanical system satisfies Standard 62 requirements. On their field trip, the researchers measured respirable ETS particles up to 500 micrograms per cubic meter; mean respirable particles were 200 micrograms per cubic meter.

    The EPA recommended level is 15 micrograms per cubic meter.

    According to expert sources, there are 16 deaths from heart diseases and lung cancer for every 100 workers/100 micrograms of respirable ETS particles/cubic meter, Repace said. "We are way up in the unacceptable load." It would take 100,000 cfm of air/occupant to get ETS particles to an acceptable risk level. Those would be tornado-like levels of ventilation.

    When smoking was still allowed in the Wilmington pub, ETS levels in the pool hall were more than 1,000 micrograms per cubic meter. After the smoking ban, carcinogen levels dropped 95 percent. "You can't do that with ventilation," Repace stated. The Boston pub had similar results before and after smoking bans.

    Repace's message to ASHRAE was simply this: "Cognizant authorities state that ETS kills. Ventilation is not a control for secondhand smoke." It is not expected to be one in any industrial setting.

    Publication date: 03/15/2004