Sensory evaluation of emissions from selected building products exposed to ozone

Abstract

The interaction of ozone with eight different building products was studied in test chambers. The products were plasterboard, two types of paints on plasterboard, two types of carpet, linoleum, pinewood, and melamine-covered particleboard. Four months of conditioning prior to the experiment had left the products with a low emission. The products' ability to remove ozone from the air covered a wide range. For three of the products (plasterboard with paint, carpet, and pinewood), it was shown that the removal was primarily due to interactions in the products' surfaces and only to a minor extent due to gas-phase reactions. Sensory evaluations were carried out for five of the products, with different ozone-removal potentials. A sensory panel assessed the emissions from sets of two specimens of each product; one specimen was exposed to a high, but realistic, ozone concentration (10 or 80 ppb) and one specimen was exposed to no ozone (background level < 3 ppb). The panel assessed odor intensity and was asked to choose which odor of the two specimens they preferred. The perceivable changes in emissions due to exposure of the products to ozone depended on the type of product. The greatest effect was seen for carpet. Carpet was the only product that showed significantly higher odor intensity when exposed to ozone. Besides, the effect of ozone on preference was strongest for carpet and resulted in a clear negative sensory evaluation. A similar but less pronounced effect was seen for pinewood and plasterboard with paint. No clear preference was seen for melamine and linoleum.

Ozone removal by green building materials

“…This criterion generally applies to so-called ''primary'' emissions, typically of volatile organic compounds (VOCs), which are emitted from the actual components of the manufactured product. However, measurement of primary emissions of indoor materials alone may not be sufficient, since secondary emissions that are generated from ozone reactions with those materials may dominate over the time that a product is in use [21]. Understanding ozone reactivity with green materials is an important first step toward understanding the potential for secondary emissions from such materials, as well as for determining green materials that effectively remove ozone without significant formation of by-products.…”

Reactions between ozone and building products: Impact on primary and secondary emissions

“…Reactions of ozone modify primary emissions of building products causing secondary emissions of aldehydes (Weschler et al 1992, Morrison and Nazaroff 2002, Nicolas et al 2003) and odorous compounds (Knudsen et al 2003).…”

Sensory and chemical evaluation of odorous emissions from building products with and without linseed oil

“…This may be due to e.g. reactions with ozone [1][2][3]. During this process unwanted odour-active chemical compounds can be formed that may influence the perceived air quality negatively.…”