Volatile organic compounds were determined in headspace atmospheres over samples of cotton (Gossypium hirsutum L.) and polypropylene {[CH2CH(CH3)]n} at 100 and 150°C in He and air. A small number of volatile organic compounds were released from cotton at 100°C in He with comparatively low emission rates of 0.2 to 0.3 µg g-1 per component. These components had C numbers below 21. In contrast, emission rates for volatile organic compounds from polypropylene-based tarp were 0.6 to 9 µg g-1 at 100°C in He, and constituents were predominantly alkanes with C numbers of 14 to 19. Increases in emission rates were observed for components with low vapor pressures (i.e., C numbers >16) though little increase was observed for components with high vapor pressures (i.e., C numbers <16). Exposing cotton to an air atmosphere at 150°C created dramatically new chromatographic profiles for volatile organic compounds versus those from inert atmospheres, and emission rates per compound increased to 0.4 to 1.3 µg g-1. Changes in volatile organic compound emissions for polypropylene-based tarp in air were less noticeable at 150°C, though emission rates per compound increased to 0.8 to 11 µg g-1. Some compounds produced in air at this higher temperature were suggestive of oxidative decompositions. Prolonged heating of polypropylene-based tarp resulted in thermal desorption of residual solvents or impurities followed by thermal decomposition.
