The overall rationale for the development of a labelling system to account for building products' emissions of volatile organic compounds (VOCS) is threefold: 1) The primary emission of VOCs from new building products may decline over a time span of months. Field studies have indicated tentative decay periods for the emission of VOCs in a new building ranging from 3 to 12 months, while half-life decay rates have been measured from 2-8 weeks. 2) VOCs may have a certain impact on deterioration of the indoor air quality (IAQ) and they may increase the probability of SBS reporting. 3) Energy efficient, i.e. tight, but ."sick" buildings may cost society more than is gained by energy savings, rather it appears that the best way to control and reduce indoor air pollution of VOCs emitted from building, products is "source control" by evaluation and proper selection of building products. 

The first attempt to combine emission testing of building products with a health assessment of the emitted VOCs using indoor relevant odour and irritation thresholds, in addition to other non-endpoint health effects, has appeared recently. Previously, a rating, system has been suggested to classify the emission of VOCs from building, products into three classes. In this system, the emissions from a product are rated according to their Iong-term effects as carcinogens, mutagens, allergens, and allergens, in addition to short-term effects such as mucous membrane irritation and odour annoyance. However, the aspect of emission decay was not considered. A French study of the emission profiles of consumer products has applied occupational threshold limit values coupled with modeled concentrations using, a compartment model. The American carpet dialogue ranks the total emission of VOCs (TVOC) after 24 to 96 hours without reference to the potential health impact. The Washington State requires security for safe new buildings with regard to the IAQ and demands compliance with specific air quality standards for formaldehyde, TVOC, 4-phenylcyclohexene from carpets, all of which have to reach certain standards within 30 days of installation The Swedish Flooring Trades Association has specified that the emission rates should be measured in the micro chamber FLEC after 4 and 26 weeks, respectively, and expressed in TVOC Units/(m*h). In a study, 50 different flooring materials (linoleum and PVC) showed that the emission rate had been reduced to about two-thirds after 26 weeks.