Mt. Irazu has explosive eruptions. Some hazards include mudflows, and tephras. The volcano's fumaroles also release toxic steam which could pollute the nearby air. Irazu's volcano has basaltic magma. The soil around Irazu has allowed for 3 types of forests to develop; Premontane Rain Forest, Montane West Forest, and Montane Rain Forest. These include Alder, Black Oak, and Copey trees.