Healthy Indoors Magazine

March-April 17

Healthy Indoors Magazine

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FEATURE—March/April 2017 16 HCHO – The Chemical Alternatively Known as Formaldehyde By Sarah Mack Active sampling controls the air flow with a calibrat- ed sampling pump which results in a more accurate sample volume. Active sampling is more of a snap shot in time and does not consider fluctuations in tempera- ture or humidity over a longer period (e.g. 24 hours) that might affect occupants. Room sampling includes all sources of formalde- hyde in the space as part of the total and not just one specific product. This does make it a bit more difficult to determine the key contributors when an elevated value is returned from the lab. Product sampling can be helpful when trying to compare differences in formaldehyde emissions be- tween two potential sources in the home. Product sam- pling is not generally useful for determining occupant inhalation exposure risk. Compliance testing, as referenced in the March 2015 news episode, is typically performed under spe- cific conditions and applies to components of the prod- uct, not the final fully-assembled product. As such, it is almost impossible to replicate the compliance testing conditions once the material is installed in a residential or commercial building. Back to the scenario…you performed the testing and you have the numbers. That was the easy part. Now to interpret and regurgitate the results in such a way that the consumer understands all while keeping in mind your sampling method's limitations. Formaldehyde Exposure and which Exposure Limit to use? Formaldehyde exposure can have serious health conse- quences, especially for asthmatics and individuals that suffer from multiple chemical sensitivities (MCS). Expo- sure to formaldehyde can lead to respiratory distress, Headlining F ormaldehyde exposure risks recently came to the front of public awareness fol- lowing a 2015 CBS 60 Minutes episode describing elevated formaldehyde levels from composite wood flooring manufac- tured in China. [1] This issue led to gener- al confusion and concern for home and business owners who had laminate flooring installed in their buildings. Health concerns were heightened for all consumers who used similar products. Formaldehyde is on the minds of many (again). Flooding Fan Mail Web searches for Formaldehyde filled search engines, the email requests for quotes or scheduling sent with light- ning fast speed, and phones rang for weeks and months. Indoor Air Professionals went scrambling to their labs for Formaldehyde testing options. Even though many could explain the general concerns of formaldehyde exposure, the public demanded numbers. Testing Methods In general, for formaldehyde testing, the question of which technique and conditions give the most represen- tative results is critical: passive (i.e., badge monitoring) vs active (i.e., pumped) sampling; room sampling vs product off-gas sampling vs. compliance testing. What to consider for each: Passive room sampling relies on diffusion of formalde- hyde into a sampling device such as a badge. The badge typically needs to be in place at least 24 hours to get a val- id reading. Passive sampling results typically have greater uncertainty because variations in air flow and environmen- tal conditions can cause changes in the diffusion rate. [2]

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