Scientists from the Danish Technical University held an investigation to find out state of health and operational capacity of workers in ill-ventilated offices covered with old carpets. Specialists from the Center for environmental safety of living and public quarters, attached to the University, held an experiment with an old carpet that had been used for twenty years in one of the offices and was never cleaned. Volunteers, who agreed to participate in the experiment had to spend four hours in the rooms, where pieces of the carpet were placed in the corners. At that the people had to perform regular office work. As was expected, the operational capacity of the people was lower than the average rate, as they were half asleep because of the carpet emanation. The people felt giddiness, sickness and headache, preventing them from concentrating on work. Results of the experiment were reported at the International conference on microclimate in offices.