Oil of Vitriol; Sulfuric Acid

Hello! And welcome to this brief overview of Sulfuric Acid! My name is Stacey Dillion, and I am here to present a few facts on this corrosive solvent.

I chose this topic based on what can only be described as a series of unfortunate events. Long ago in a kingdom far far away, I was working in a lab where this solvent was a frequent visitor. I would love to explain why, but my confidentiality agreement is outstanding until at least 2028. Long story short; a large bottle dropped, someone was burned through their Tyvek suit and rubber boots, and we watched the drain cover begin to sizzle as the acid went down into the pipes. Facility Hazard Response Teams were less than thrilled, and there was a lot of paperwork. The end!

Please be advised; the media in the content below are derived from both multimedia and published literature. Figures with numeric representation are those found in the corresponding literature, those with alphabetic representation are derived from multimedia.

With any luck, this post will help explain why that series of events was so dangerous, and maybe – just maybe – someone reading this will learn from our mistakes and stay safe!

SO! Without further ado – I present to you Sulfuric Acid!

 

Sulfuric Acid is a highly corrosive substance. It is colorless, odorless, and a viscous liquid that is miscible with water. “Miscible with water” roughly translates to a vigorous exothermic reaction that can boil, spit, and leave painful acid burns if the skin is exposed. 100%, non-diluted sulfuric acid is pictured in image (a)

• Source (1, 3)
  • As the name implies, sulfuric acid comes from Sulphur. Sulphur dioxide is created by molten sulfur in the presence of air.

 

• • Natural sources include the oceans, biological decay, and forest fires. Roughly 75% of released sulfur dioxide is from the burning of fossil fuels. 25-30% comes from burning oil, and the remainder comes from burning coal.
    • Combustion of sulfur dioxide creates sulfur trioxide, which is released into the air. When combined with water, sulfur trioxide becomes sulfuric acid.
    • Sulfuric acid can be suspended in the air for some time, but when it precipitates, it falls as rain. This phenomenon is known as “Acid Rain”
      • 

        (b) The Effects of Acid Rain on The Leshan Giant Buddha

        Image (b) is a photo taken of The Leshan Giant Buddha. This figure was carved out of the hill in the 1st century C.E (Common Era) and has suffered the effects of acid rain for decades.

• • Synthetic sources are lab-created utilizing chemical combinations of sulfur, oxygen and hydrogen. The chemical formula is H₂SO₄.

 

 

 

 

• Biotransformation (1, 3)
  • Sulfuric acid is highly reactive and dissolves most metals
    • It is a concentrated acid that oxidizes, dehydrates, or sulfonates most organic compounds. This often causes charring. For a fun visual, please see the “Added Bonus” section at the bottom of this post and enjoy the video!

 

• • Sulfuric acid reacts violently with alcohol and water, releasing heat
    • If briefly diluted with water, the acid can form a flammable hydrogen gas. This is typically considered an explosion hazard.

 

• • This acid is not combustible, but it is a strong oxidizer. Meaning; sulfuric acid does not burn, but it enhances the combustion of other substances.

 

• • Biotransformation in this case is not limited to whether the acid becomes structurally modified. Toxicities result as a catalyst for the reaction of sulfuric acid with water and/or oxygen
    • This is due to pH changes rather than the sulfate itself

 

 

• Toxicokinetics (3)
  • Absorption can be through direct contact (skin) or via inhalation
    • Clearance through the lungs can be very rapid depending on the dose exposed

 

• • Distribution can be difficult to determine as sulfate is a normal constituent of blood and toxicity is (typically) solely limited to local contact vs. systemic circulation

 

• • Metabolism can also be difficult to determine based on the normal presence of sulfur in blood. Sulfur trioxide in contact with water forms sulfuric acid with the evolution of heat. In the absence of extreme heat (roughly 450◦F) and continued exposure to water, sulfuric acid will dissociate into hydrogen ions and hydrogen sulfate ions, which are combined throughout the body. Sulfate does not need to be further metabolized to be excreted.

 

• • Excretion of sulfuric acid following dissociation is through urine

 

• Carcinogenicity (4)
  • Chronic exposure of sulfuric acid through mist or inhalation can often go unnoticed, however the International Agency for Research on Cancer (IARC) has classified this solvent as a Group 1 carcinogen.
    • Group 1 carcinogens claim sufficient evidence of cancer-causing capabilities in humans

 

• Mechanism of Action (3, 4)
  • The effects of sulfuric acid are due to the presence of the H+ ion and pH changes rather than the sulfate itself.
    • The number of hydrogen ions in a strong acid is reduced, thus causing the pH to lower.

 

• • Toxic effects of sulfuric acid are localized to the point of contact (skin, eyes, mouth) and are due to the protonation of protection molecules like keratin.
    • This weakens the surface of the tissue and makes it more susceptible to damage
      • The images for the effects of sulfuric acid on skin are quite graphic. I will let each reader search at their own discretion, however image (e) below is an example of a minor chemical burn that an occur in rapid time. Please understand that what you see is considered minor, thus any major injury can be deadly. The potential for catastrophic tissue damage is very high. Remember to use extreme precaution when handling.
        

        (e) Minor Effects of Sulfuric Acid on Skin

 

• Target organ(s) (3)
  • Target organs include any that are directly locally exposed to sulfuric acid
    • These typically include the eyes, mouth/teeth/gums and skin
      • The lungs and GI can be affected if the acid is in mist-form and swallowed or inhaled

 

• • Strong inorganic acids are extremely hazardous and can burns to the skin and eyes if direct contact is made.

 

• Signs and symptoms of toxicity (acute and chronic)(2, 4)
  • Signs and symptoms of toxicity are typically acute.
    • Sulfuric acid reacts with tissues and cells on contact.
      • Tissue injury appears within seconds of exposure and can continue for hours if not treated
    • Damage can range from irritation to chemical burns and necrosis at the site of contact
      • The extent of the damage is dependent on the dose received, length of exposure prior to treatment, and the molar concentration (strength) of the sulfuric acid solution
        • the higher the concentration, the greater the extent of the damage.

 

• • Chronic exposure can lead to tissue necrosis and severe chemical burns with scarring. Chronic exposure has also been linked to multiple cancers, including lung and skin, if the acid is in mist form.

 

• Treatments (3)
  • There are no medical tests to determine exposure to sulfuric acid
    • Breathing acid will alter the pH of saliva, but it cannot be determined which acid caused the exposure

 

• • Acute exposures can be treated with mild soapy solutions if the burns are not severe
    • The skin may feel hot, but the continued exposure to water will flush the acid off
    • Severe burns can be treated with continued flushing of the area exposed and standard-wound dressing for burns
      • Patients will likely be in pain, so pain management is also expected

 

• • Chronic exposures are likely unknown until patients present with malignancies. Treatment for sulfuric-acid related cancers would follow the care regimens in place for those specific malignancies

 

• Genetic susceptibility or heritable traits (3)
  • Sulfuric acid is highly acidic; it’s main uses are for the cleaning of metals, removal of impurities in oil, and the manufacturing of chemicals.

 

• • It can also be used in fertilizers, pigments and dyes, drugs, explosives, detergents, petroleum refining, and metallurgy.

 

• • Due to the wide variety of uses, there are no limits for who can be exposed
    • Susceptibility would be greater to those who are working with sulfuric acid directly

 

• • No heritable traits have been identified in those exposed to sulfuric acid

 

• Historical or unique exposures (5)
  • In 1984, scientists deliberately acidified Little Rock Lake, Wisconsin. The pH was intentionally decreased from 6.1 to 5.6, 5.1, and 4.7. The lake was allowed to recover from the fall of 1990. Image (c) demonstrates the pH scale of commonly found materials.

• • The experiment was conducted to evaluate the environmental effects of high acid and the natural acid neutralizing capacity (ANC) of the inhabiting fish populations. Image (f) is a photo of the aftermath.
    • While some recovery was observed, researchers believe the recovery has not closely followed the patterns predicted and several species are unable to fully reproduce as they would have without manipulation of their natural environment
      

      (f) Little Rock Lake, Wisconsin

 

• Biomarkers (6)
  • Acidity is the best indication for the presence of sulfuric acid in the environment
    • Measurement and monitoring for sulfuric acid is typically conducted by the Environmental Protection Agency (EPA). The greatest cause of concern is acid rain
      • Rain typically has a pH of around 5.6; it is slightly acidic due to carbon dioxide
      • Acid rain has a pH between 4.2 and 4.4
    • Monitoring is typically the task of the National Atmospheric Deposition Program’s (NADP) National Trends Network (NTN)
      • The NADP/NTN collects rain at more than 250 sites worldwide and measures for pH
    • Soil is also measured and monitored by the Clean Air Status and Trends Network (CASTNET)
      • The nitrogen and sulfur pollutants are provided from more than 90 world-wide locations

 

• Essentiality and deficiency 
  • Sulfuric acid has many uses and is an effective solvent when utilized under the proper conditions. However, due to its extreme corrosive potential, harmful environmental effects, and carcinogenic capabilities, I cannot in good conscience identify this solvent as essential. It seems that deficiency is more favorable.

 

• Added bonus
  • This video shows multiple items exposed to sulfuric acid. It doesn’t really “get good” until about 2 minutes in, so please have some patience. Please also don’t do what this guy did and handle these materials with bare hands! If you take nothing else away from this post, just remember that sulfuric acid is extremely corrosive and will cause injury. Wear gloves, wear eye protection, and always have a large source of clean water close by!(d)

 

Content References:

1. Saeid, A., and K. Chojnacka. “Sulfuric Acid.” ScienceDirect, Academic Press, 1 Jan. 2014, sciencedirect.com/science/article/pii/B9780123864543009908. Accessed 01 JULY 2022.

 

2. Robles, Heriberto. “Sulfuric Acid.” ScienceDirect, Elsevier, 1 Jan. 2005, sciencedirect.com/science/article/pii/B0123694000009121. Accessed 01 JULY 2022.

 

3. TOXICOLOGICAL PROFILE for SULFUR TRIOXIDE and SULFURIC ACID Agency for Toxic Substances and Disease Registry. 1998. https://www.atsdr.cdc.gov/ToxProfiles/tp117.pdf Accessed 01 JULY 2022.

 

4. Yang JH, Koedrith P, Kang DS, et al. A Putative Adverse Outcome Pathway Relevant to Carcinogenicity Induced by Sulfuric Acid in Strong Inorganic Acid Mists. J Cancer Prev. 2019;24(3):139-145. doi:10.15430/JCP.2019.24.3.139. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6786810/

 

5. Sampson, C.J., Brezonk, P.L., Frost, T.M. et al. Experimental acidification of Little Rock Lake, Wisconsin: The first four years of chemical and biological recovery. Water Air Soil Pollut 85, 1713–1719 (1995). https://doi.org/10.1007/BF00477227

 

6. United States Environmental Protection Agency. “What Is Acid Rain?” US EPA, United States Environmental Protection Agency, 12 May 2020, www.epa.gov/acidrain/what-acid-rain.

 

Multimedia References:

(a) “Tips for the Process Measurement of Sulfuric Acid from 0 to 110 Percent.” Www.process-Worldwide.com, process-worldwide.com/tips-for-the-process-measurement-of-sulfuric-acid-from-0-to-110-percent-a-827001/.

 

(b) Affected Landmarks. sahilacidrain706.weebly.com. Accessed July 1, 2022. https://sahilacidrain706.weebly.com/affected-landmarks.html

 

(c) United States Environmental Protection Agency. “What Is Acid Rain?” US EPA, United States Environmental Protection Agency, 12 May 2020, www.epa.gov/acidrain/what-acid-rain.

 

(d) “How Sulphuric Acid Reacts with Different Things.” Www.youtube.com, www.youtube.com/watch?v=DVAbwqlMh1E. Accessed 1 July 2022.

 

(e) “Hydrochloric Acid on Skin: Effects and Treatments.” Skin Care Geeks, 28 Feb. 2020, skincaregeeks.com/hydrochloric-acid-on-skin/.

 

(f) Native plants become a weapon in battle to save algae-choked Little Rock Lake. MPR News. Accessed July 1, 2022. https://www.mprnews.org/story/2019/08/06/photos-saving-little-rock-lake-by-drawing-down-the-water-central-mn