Measured emissions from building materials (Part I, Nielsen et al., 1996), were evaluated for their sensory effects, odour and irritation, as well as for health effects. The procedures adopted are general. First, if established indoor air standards or guidelines are available, they are to be preferred for the evaluations. Second, if they are not available, odour and irritation thresholds are used. The occupational exposure limits may be used for the evaluation of health effects if applying an additional safety factor between 4 and 40. The actual value depends on the critical effect, but a safety factor of 40 is proposed as a first approximation. Other values must be justified. Third, if occupational exposure limits are not available, two different procedures provide a tentative standard or guideline on the basis of published literature, which of necessity must therefore be collected and evaluated. One procedure estimates the standard from an effect in animals and applies a number of safety factors (each often equal to 10), corresponding to a series of worst‐case assumptions. The other procedure evaluates the critical effect and uses fewer specific safety factors to predict the human no‐observed‐effect level (NOEL). The political safety factor is then determined, i.e. how far below the NOEL the standard or guideline level should be set. The last‐mentioned procedure gives a logical concordant system, explaining why different standards or guidelines may be set for outdoor, indoor and occupational exposures, and why exposures exceeding a standard or a guideline need not cause health effects.

Monthring of human reactions to the emission of fmmaldehyde and volatile organic compounds (VOC)from four commonly used building materials was carried out. % building materials were: a painted gvp sum board, a rubber floor, a nylon c w t , and a particle board with an acid-curing paint. % exposures

Quantitative structure-activity relationships (QSAR) have suggested the importance of hydrogen bonding in relation to activation of the sensory irritant receptor by nonreactive volatile organic chemicals. To investigate this possibility further, three model compounds with different hydrogen bond acidity, trifluoroethanol, hexafluoroisopropanol and methyl hexafluoroisopropyl ether, were selected for study. The potency of each chemical is obtained from the concentration necessary to reduce respiratory rate in mice by 50% (RD50). The RD50 values obtained were: methyl hexafluoroisopropyl ether (> or = 160,000 ppm), trifluoroethanol (11,400-23,300 ppm), and hexafluoroisopropanol (165 ppm). QSAR showed that trifluoroethanol and methyl hexafluoroisopropyl ether behaved as predicted as nonreactive sensory irritants, whereas hexafluoroisopropanol was much more potent than predicted. The higher than predicted potency of hexafluoroisopropanol could be due to a coupled reaction, involving both strong hydrogen bonding and weak Brönsted acidity. A concerted reaction could thus be more efficient in activation of the receptor. Hydrogen bonding properties and concerted reactions may be important in the activation of the sensory irritant receptor by nonreactive volatile organic chemicals.

The purpose of this study was to evaluate whether asthmatic reactions and changes in tear film quality could be prmohd by exposing subjects to missions from building materiuls in climate chambers. Twenty asthmatics and 5 healthy controls were exposed to (I) gypsum board hung with waterbonze painted wallpaper; (2) rubber floor covering; (3) n y h carpet with rubber mat; (4) particle board coated with acid-curing paint; and (5) m test materials in climate chambers for 6 h. Participants recorded symptoms by filling in questionnaires, and clinical data were evaluated by lung Fax No. + 45 35 45 75 49finction measurmts at intervals of 30 min to I h, and external eye examinutwns before and after exposure (appeaTance of foam at geld, smi-quantitative measuremmts of precorneal superjicial lipui h y q break-up time and epithelial damage). 7ha-e was agreement benueen a trained panel's evaluation of perceived air quality and the participants' opinion of in-dooT air quality. No correlation was found benueen lungfinction measurements and exposure to the materials. However, for all materials, statistically significant changes in tear film quality were observed to vay'ng a'egrees. Lipophilic E' olatile Organic Compounds (VOCs) may htabzlize the lipui mulhyer of the tear fluid, and this mechanism is suggested to be at least partly responsible for eye im'tation.

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