Literature review | Indoor air quality | Jan 18, 2020

      How we assess indoor air quality

      As described in an excerpt from Scientific Update 9

      TIME TO READ: 2.5 MIN

      How would you know whether the quality of the air you’re breathing is poor? To some, the first indication might be visual; for example, smog or black smoke. But the presence of something visible doesn’t reveal how harmful the compounds in the air can be. The best way is to analyze those individual airborne compounds regardless of their smell or color.

      An illustration showcasing measuring indoor air quality at home, office and restaurant.

      Assessing air quality is an important factor of the science behind our smoke-free products – in this case our Electrically Heated Tobacco System (EHTS) – as it provides a strong indication of the potential impact that a product’s use may have on bystanders. So how exactly do we measure air quality? By analyzing the effect of EHTS and cigarettes, compared to background air. We explored this influence over three settings: home, office, and restaurant. Then we simulated each of these in a lab by varying the number of people occupying the space, and the amount of air being circulated – based on the European ventilation performance standard.

      The office setting involved three people and a ventilation rate (the amount of air being pumped into/out of the room) of 156 m3/hour. The restaurant environment involved five people in total, paired with a ventilation rate of 555 m3/hour. The scenario for home tests used the same number of participants, but with an 87 m3/hour ventilation rate. Additionally, another study we carried out later focused exclusively on the home setting, involving three people at 37 m3/hour.

      Ventilation rates of different settings
      Restaurant: 555 m3/hour = 7.68 air changes
      Office: 156 m3/hour = 2.16 air changes
      Home: 87 m3/hour = 1.2 air changes, and 37 m3/hour = 0.5 air changes.

      To ensure accurate measurements and no cross-contamination, we air-washed the room overnight with a ventilation rate of 750 m3/hour of clean filtered air, and the furniture was cleaned with a water-ethanol mixture. To establish a background baseline, the air quality was also determined before any EHTS or cigarette use.

      The order of events for each test was: air wash, background measurement, another air wash, then EHTS or cigarette use. We evaluated 18 different compounds for all three settings, and 24 compounds in the additional home environment study (all listed in the 'Compounds tested' section below), for both EHTS and cigarette use. Across the settings, EHTS use showed no significant difference compared to background air for 16 of 18 measured compounds, and the two that were higher – nicotine and acetaldehyde – were still far lower than the existing guideline levels. Comparatively, cigarette use showed a significant difference in all 18 compounds versus background levels, and at higher levels than EHTS. This led us to conclude that the use of EHTS in an indoor environment does not adversely affect the overall indoor air quality.

      An illustration showcasing measuring indoor air quality at home.

      These are two of many studies we’ve carried out on the indoor air quality effects of EHTS. Our research has also covered the effects of EHTS on the air quality of day-to-day activities, entertainment environments, stores, and other real-world settings which resulted in the same conclusion; no negative impact on the overall indoor air quality. These are outlined in our report of EHTS’s lack of environmental tobacco smoke, which also provides an overview of independent studies researching our product’s impact on indoor air quality.


      Compounds tested

      These 18 were selected as a representation of standard air quality markers, and markers non-specific and specific to EHTS aerosol or cigarette smoke:

      • 1,3-Butadiene
      • 3-Ethenylpyridine
      • Acetaldehyde
      • Acrolein
      • Acrylonitrile
      • Bezene
      • CO
      • Crotonaldehyde
      • Formaldehyde
      • FPM
      • Isoprene
      • Nicotine
      • NO
      • NOx
      • RSP
      • Solanesol
      • Toluene
      • UVPM

      The additional study also measured:

      • Glycerin
      • NNK
      • NNN
      • PM1/PM2.5
      • Propylene glycol
      • TVOCs

      Note: studies such as these are part of our product scientific assessment program, not part of regulatory efforts to affect public smoking bans.

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