Facilities without or with poorly dimensioned ventilation systems often struggle with maintaining a clean and healthy air. This means that there are elevated concentration levels of air pollutants such as dust, viruses, bacteria, pollen, mold spores, combustion particles, and outdoor pollution contaminating the indoor air. Schools, gyms, and offices also sometimes experience bad odors and volatile organic compounds. Exposure to polluted air causes sicknesses and allergies both in short and long term. This in turn lead to increased absences and decreased productivity, as well as making your business less attractive. By using the FS 35 Standard, all these types of particles can be reduced, creating a healthier and cleaner indoor environment.