What are the effects of fiberglass on the human body?

Due to the brittle nature of glass fibers, they break into shorter fiber fragments. According to long-term experiments conducted by the World Health Organization and other organizations, fibers with a diameter of less than 3 microns and an aspect ratio of more than 5:1 can be inhaled deep into the human lungs. The glass fibers we commonly use are generally larger than 3 microns in diameter, so there is no need to be overly concerned about lung hazards.

In vivo dissolution studies of glass fibers have shown that microcracks present on the surface of glass fibers during processing will widen and deepen under the attack of weakly alkaline lung fluids, increasing their surface area and decreasing the strength of the glass fibers, thus accelerating their degradation. Studies have shown that glass fibers completely dissolve in the lungs in 1.2 to 3 months.

According to previous research papers, long-term exposure (more than one year in both cases) of rats and mice to air containing high concentrations of glass fibers (more than one hundred times the production environment) had no significant effect on lung fibrosis or tumor incidence, and only implantation of glass fibers within the pleura of the animals revealed fibrosis in the lungs. Our health surveys of workers in the glass fiber industry in question did not find a significant increase in the incidence of pneumoconiosis, lung cancer, or pulmonary fibrosis, but did find that the lung function of said workers was reduced compared to the general population.

Although glass fibers themselves do not pose a danger to life, direct contact with glass fibers can cause a strong sensation of irritation to the skin and eyes, and inhalation of dust particles containing glass fibers may irritate the nasal passages, trachea, and throat. Symptoms of irritation are usually non-specific and temporary and may include itching, coughing or wheezing. Significant exposure to airborne fiberglass may aggravate existing asthma or bronchitis-like conditions. Generally, the associated symptoms subside on their own when the exposed person moves away from the source of the fiberglass for a period of time.