The most hazardous chemical used in fiber glass industry are: formaldehyde, phenol and ammonia. The chemicals were monitored in an industry in Kuwaitto investigate the indoor air quality of the facility. It was found that all these chemicals were within the OSHA standards but formaldehyde exceeded KEPA standards (0.1 ppm) in the curing area. It was found that lower density of fiber glass product leads to higher concentration of pollutants in the atmosphere andvise versa. Moreover, higher thickness causes higher concentration of pollutants in the atmosphere.