Many types of occupational activities determine formaldehyde (FA) exposure. FA inhaled causes oxidative stress, activates Caspase-3, -6, and -7, and causes apoptosis in nasal epithelial cells. Inhalation of FA has also been shown to cause cell proliferation and tissue damage. Free radicals and oxidative damage can be prevented and inhibited by antioxidant compounds, one of which is Sappan wood (Caesalpinia sappan L).