Isocyanates Emission Tests from Polyurethane Products

YUJI FUJITANI, Yoshikatsu Takazawa, Go Suzuki, Satoshi Inomata, Rie Yanagisawa, Eiko Koike, National Institute for Environmental Studies

     Abstract Number: 4
     Working Group: Indoor Aerosols

Abstract
The study evaluated the emission of isocyanates from automotive seat components and cushions using a microchamber method, based on JIS standards for assessing semi-volatile organic compounds (SVOCs) released from building materials. A 13L quartz glass chamber was used to control temperature and humidity while circulating air at 20 mL/min for 24 hours. The emission rate of 2,4-TDI was found to be 25-67 ng/m²/hour under conditions of 28°C and 50% relative humidity. As temperature and humidity were increased (e.g., 45°C and 60°C), the emission rate of 2,4-TDI increased significantly, with a 20-fold increase observed at 60°C compared to 28°C. The study also found that higher humidity led to faster emission rates. Furthermore, the emission of particles was evaluated using a CPC. When no piece of test samples in the quartz glass chamber were present, the particle concentration was zero. With one piece of sample, the particle concentration increased, and a higher temperature led to an increase in particle concentration. The study confirmed that urethane samples emitted particles. The calculated particle emission rates were 1-24 × 10⁶ particles/m²/hour. Overall, the study demonstrated the relationship between temperature, humidity, and the emission of both isocyanates and particles from automotive seat materials and cushions, providing important data on the potential exposure to harmful substances in living environments.