Download PDF MDI is a common type of isocyanate, which is the chemical used to start the curing process of polyurethane foams. How can this chemical affect my health? Acute (Short Term) Effects Toxic to Humans & Animals – Can be fatal on contact, ingestion or inhalation for humans and other mammals. Irritates the Eyes – Can cause irritation or serious damage to the eye. Irritates the Skin – Can cause irritation or serious damage to the skin. Chronic (Long Term) Effects Cancer – Can cause or increase the risk of cancer. Birth Defects – Can cause harm to the developing child including birth defects, low birth weight and biological or behavioral problems that appear as the child grows. Asthma Trigger – Can result in high sensitivity so that small quantities trigger asthma, nose or sinus inflammation or other allergic reactions in the respiratory system. Other Health Effects – Can cause serious damage on contact or ingestion.