neoFroxx® Sulfuric Acid - Dimensional Solution 0.05 M (0.1 N), CAS: 7664-93-9

Used in the fertilizer, petroleum refining, and battery industries; also used in metal cleaning and electroplating; [ACGIH] Used in printing, publishing, and photography shops; [ATSDR ToxFAQs] Used as a wet etchant in semiconductor manufacturing at a standard concentration of 96%; [CSH, p. 46]

ACGIH - Documentation of the TLVs and BEIs, 7th Ed. Cincinnati: ACGIH Worldwide, 2020.

Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Sulfuric acid aerosol toxicity is dependent on the hydrogen ion content of the aerosol. One mechanism by which sulfuric acid may produce its toxicity is by changing extracellular and intracellular pH. There is evidence that pH plays a critical role in growth control and cell differentiation, and that disrupting the control of pH may lead to adverse effects A sufficiently low pH is genotoxic to some cell systems. Therefore, a significant change in pH produced by sulfuric acid exposure could potentially lead to cellular changes if hydrogen ions reached susceptible targets. A preliminary in vitro study that exposed a human tracheal epithelial cell line to sulfuric acid aerosols of 0.75, 1.4, or 3.28 um for 10 minutes revealed that intracellular pH decreased, and, that at equal mass concentrations, the change in pH was greater for the smaller particle sizes.

U.S. Dept Health & Human Services/Agency for Toxic Substances & Disease Registry; Toxicological Profile for Sulfur Trioxide and Sulfuric Acid pp. 83-4 (December 1998). Available from, as of June 17, 2016: https://www.atsdr.cdc.gov/toxprofiles/tp117.pdf

Hazardous Substances Data Bank (HSDB)

Mechanisms of sulfuric acid-induced pulmonary injury have been studied. Atropine was administered to 12 guinea pigs in order to inhibit reflex-mediated bronchoconstriction and the animals were exposed to 32.6 mg/cu m sulfuric acid aerosol (MMAD /mass median aerodynamic diameter/ 1.0 um, relative humidity 70-90%) for 4 hr Unlike guinea pigs who were exposed to sulfuric acid without atropine pre-treatment, the atropine-treated animals had no signs of pulmonary injury, such as epithelial desquamation. It was concluded that pulmonary injury following sulfuric acid exposure may be due in part to mechanical forces generated during reflex-mediated bronchoconstriction.

U.S. Dept Health & Human Services/Agency for Toxic Substances & Disease Registry; Toxicological Profile for Sulfur Trioxide and Sulfuric Acid p. 84 (December 1998). Available from, as of June 17, 2016: https://www.atsdr.cdc.gov/toxprofiles/tp117.pdf

Hazardous Substances Data Bank (HSDB)

The genotoxic effects of significantly lowered pH may contribute to the ability of sulfuric acid to produce respiratory tract tumors. It has also been postulated that sulfuric acid may promote carcinogenesis by inducing chronic tissue irritation Chronic inflammation results in the release of free radicals which have a genotoxic action. In addition, chronic inflammation may increase susceptibility to infection which may contribute to a carcinogenic response. However, the mechanism of carcinogenesis remains to be proven.

U.S. Dept Health & Human Services/Agency for Toxic Substances & Disease Registry; Toxicological Profile for Sulfur Trioxide and Sulfuric Acid pp. 84-5 (December 1998). Available from, as of June 17, 2016: https://www.atsdr.cdc.gov/toxprofiles/tp117.pdf

Hazardous Substances Data Bank (HSDB)

The effects of sulfuric acid are the result of the H+ ion (local deposition of H+, pH change) rather than an effect of the sulfate ion. Sulfuric acid per se is not expected to be absorbed or distributed throughout the body. The acid will rapidly dissociate and the anion will enter the body electrolyte pool, and will not play a specific toxicological role.

OECD; SIDS Initial Assessment Reports for Sulfuric Acid (CAS No: 7664-93-9) for 11th SIAM (January 2001). Available from, as of July 29, 2016: https://www.inchem.org/documents/sids/sids/7664939.pdf

Hazardous Substances Data Bank (HSDB)