Highly corrosive; causes severe burns on eye and skin contact and upon inhalation of sulfuric acid mist; highly reactive, reacts violently with many organic and inorganic substances.

Concentrated sulfuric acid is a highly corrosive liquid that can cause severe, deep burns upon skin contact. The concentrated acid destroys tissue because of its dehydrating action, while dilute H ₂SO₄ acts as a skin irritant because of its acid character. Eye contact with concentrated H₂SO₄ causes severe burns, which can result in permanent loss of vision; contact with dilute H₂SO₄ results in more transient effects from which recovery may be complete. Sulfuric acid mist severely irritates the eyes, respiratory tract, and skin. Because of its low vapor pressure, the principal inhalation hazard from sulfuric acid involves breathing in acid mists, which may result in irritation of the upper respiratory passages and erosion of dental surfaces. Higher inhalation exposures may lead to temporary lung irritation with difficulty breathing. Ingestion of sulfuric acid may cause severe burns to the mucous membranes of the mouth and esophagus.

Animal testing with sulfuric acid did not demonstrate carcinogenic, mutagenic, embryotoxic, or reproductive effects. Chronic exposure to sulfuric acid mist may lead to bronchitis, skin lesions, conjunctivitis, and erosion of teeth.