Indoor air pollution by organic emissions from textile floor coverings. Climate chamber studies under dynamic conditions.

A study was made of the time dependence of the emission of organic compounds from a polyamide floor covering with styrene-butadiene-rubber backing in three climate chambers at 23 deg. C and 45% relative humidity. Volatile compounds such as toluene reach a maximum concentration of the gas phase in one hour, decreasing to less than 2% in 60 hours, while less volatile compounds decrease slowly over several months. Observed concentration do not depend on the chamber size, the wall material and air velocity provided the chamber is well mixed and a defined chamber loading is maintained. Observed emission concentration is roughly proportional to the chamber loading, but it is not inversely proportional to the air change rate; mass transfer from the carpet to the gas phase is enhanced at high air exchange rates. Dunn and Tichenors' 'decreasing source models' were used on the data, allowing extrapolation of experimental data beyond the time available for measurement. The presence of sink effects are shown by the models. States that the role of the chamber walls as sinks can be determined more reliably if constant sources of an organic compound are placed into the chamber and their increase in concentration with time is compared with the theoretical predictions neglecting sink effects.