Healthy Indoors Magazine - USA Edition

March-April 17

Healthy Indoors Magazine

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Healthy Indoors 17 hyde levels are elevated, then source reduction, venti- lation modification, or some other remediation method should be employed to reduce the formaldehyde lev- els. All must keep in mind that removal of materials tion and is further exacerbated by improvements in en- ergy efficiency in building construction, which leads to the unintended consequence of more efficient trapping of VOCs and formaldehyde. Wood is a natural source of formaldehyde. Combustion sources, including environ- mental tobacco smoke, typically increase formaldehyde concentration in confined spaces. Proper ventilation, as well as temperature and hu- midity control, can result in an acceptable environment even in locations where non-compliant materials are used. Conversely, concentrations may be elevated in areas where all materials of construction are compliant but ventilation may be insufficient. If room formalde- eye irritation, and other symptoms. [3] The International Agency for Research on Cancer (IARC) reclassified form- aldehyde from "probably carcinogenic to humans" to "carcinogenic to humans" in 2004. [4] Formaldehyde exposure is difficult to avoid since formaldehyde is present naturally in the environment in variable amounts ranging from less than 1 ng/L in re- mote areas to 10-20 ng/L in urban environments, [5] Ex- posure limits, whether recommended or required, vary greatly from one organization to the next. The National Institute of Occupational Health and Safety's (NIOSH) recommended exposure limit (REL) of 20 ng/L is gener- ally accepted as the number to aim for. Organization Concentration Year Comments Ng/L ppb Issued WHO 100 80 1987 0.5 hour Leed* 32 27 4 hour California 94 76 1999 1 hour (acute) 33 27 2004 8 hour (interim) 3 2 2005 Annual average (chronic) Canada 120 100 2005 1 hour 50 40 2006 8 hour UK 100 80 2004 0.5 hour Germany 120 100 1997 France 50 40 2008 2 hour (proposed) 10 8 Long-term (proposed) Norway 100 80 1999 0.5 hour 60 50 1990 2.4 hour Australia 100 80 2009 China 100 80 2003 1 hour Japan 100 80 1997 0.5 hour Hong Kong 100 81 2003 Good 30 25 Excellent Sources: Salthammer et al., Chem Rev., 2010, 2536-2572 (for all except as listed below) * Green Building Council Leadership in Energy & Environmental Desigh (LEED) Reducing Exposure (without moving to Antarctica to live in an igloo) Indoor levels are higher than outdoor levels due to off-gassing of formaldehyde from materials of construc-

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