Using too much hand sanitizer and other commercial household antibacterial products may be harmful because it can lead to antibiotic resistance, according to Healthy Child. Antibiotics are not able to deal with bacterial infections that have antibiotic resistance.
Antibacterial products can harm the body's "good" germs, which play important roles in protecting people from infections. The overuse of hand sanitizers and antibacterial soaps causes the immune system to be overly sensitized to incoming irritants, according to NBC News. This means that being too clean can cause elevated allergic set points, which may cause some people to overreact to environmental allergens.