VOC's

The summary below is from AMI documentation 2. The use has been granted by Peder Wolkoff, as seen from following mail:

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National Research Centre for the Working Environment changed  Februar 1., 2007
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AMI DOCUMENTATION 2
*Volatile Organic Compounds (VOCS) In The Indoor Envinrnment*
State-Of-The Science Report
Published by Arbejdsmiljøinstituttet, Copenhagen, 1998
Compiled by :
Peder Wolkoff, Ph.D., dr.med./D.Med.Sc
Per Axel Clausen, Ph.D.
Gunnar Damgaard Nielsen, Ph.D., dr.pharm./D.Pharm

SUMMARY

Volatile organic compounds (VOCs) are ubiquitous in the indoor environment. The most important sources of VOCs in new or renovated buildings are the primary emissions (e.g., solvents) from building products On a longterm basis, the secondary emissions (e.g. chemical or physical degradation) will dominate. The health impact of the primary emission is to sorne degree controlled by use of the established Danish Indoor Climate Labelling scheme. However, more knowledge about methods and systems to handle the secondary emissions is required in order to assess their impact on the indoor air, in particular the perceived air quality. There is no evidence that shows a casual relationship between new building product VOC emissions and sensory irritation in eyes and the upper airway in case of low formaldehyde concentrations. A major part of the general population will respond to the non-reactive VOCs at concentrations that correspond to the estimated airway irritation threshold, while only a small fraction of the population is likely to respond with a certain probability to VOC concentrations normally measured indoors. In case of a response. it is more likely that the odour perception than the airway irritation is the cause. For chemically reacive (unsaturated) VOCs the situation is different, because they react with oxidants (e.g., ozone) to form airway irritants (e.g., the hydroxyl radical). Building products with an unsaturated polyrneric structure may also be important because they may degrade by oxidant attack to form airway irriitants, in addition to VOCs that are expected to deteriorate the immediately perceived air quality.

The introduction of indoor guidelines that are based on one fortieth of occupational exposure limits is likely to protect nearly all people in the indoor environrnent, except for those with strong asthma. As a rough guide, the irnpact of VOC mixtures may be considered additive for sensory irritation and lung effeets. The combined odour intensities of VOCs in concentrations above their odour threshholds are hypoadditive, i.e. the odour intensity of the mixture is less than the sum of the single VOC (odorant) intensities. Below odour threshold, the combined odour intensity of VOC mixtures may behave by normal or hyper addition. However there is a need for better tools to model the addition of VOC odorants to predict their combined impact. In addition, more knowledge is required about the significance of cognitive effects on the perception of the indoor air quality. Available data on odour thresholds and airway irritation estimates show that the odour thresholds, to a large extent, are lower than other health endpoints, except for a few well-known VOCs (e.g., isocyanates).