reversible toxic response

Toxic responses can be classified by their outcome: reversible or irreversible. A reversible toxic response means the body can recover from the adverse effects of a substance. For example, irritation of the upper respiratory tract from formaldehyde gas is rapidly reversible; symptoms subside once exposure ends. In contrast, irreversible responses, like the formation of silicotic nodules in the lungs due to silica dust, remain even after exposure ceases.1

Toxic responses can also be morphological (structural changes) or functional (changes in how an organ works). Often, structural changes lead to functional impairment. However, some substances, like malathion, can cause functional changes by inhibiting enzymes without altering tissue structure.2