Peracetic Acid SC Gad, Gad Consulting Services, Cary, NC, USA Ó 2014 Elsevier Inc. All rights reserved.
l
Name: Peracetic Acid Chemical Abstracts Service Registry Number: 79-21-0 l Synonyms: Acetic peroxide, Acetyl hydroperoxide, Desoxon 1, Estosteril, Ethaneperoxoic acid l Molecular Formula: C2H4O3 l Chemical Structure: l
Melting point ¼ 0.2 C. Log Kow ¼ 1.07. Solubility: very soluble in ether, sulfuric acid, and ethanol; miscible with water 1.0 106 mg l1 at 25 C. Henry’s law constant ¼ 2.14 106 atm-m3 mol1 at 25 C
Partition behavior in water, sediment, and soil
Background Since the early 1900s, chlorine has been used as a water disinfectant. It was favored by water and wastewater industries for disinfection until several harmful disinfection by-products were discovered in chlorinated water. Studies were done to find and eliminate disinfection byproduct precursors and look for an alternative disinfectant, which turned out to be peracetic acid, or PAA. Peracetic acid is a chemical product belonging to peroxide compounds such as hydrogen peroxide. However, unlike hydrogen peroxide, it is a more potent antimicrobial agent. Peracetic acid has high germicidal efficiency and sterilizing capability, and its degradation residuals are not dangerous to the environment or toxic to human health. Until 1960, peracetic acid was of special interest to the food processing industry and actually was considered the only agent able to replace glutaraldehyde in the sterilization of surgical, medical, and odontoiatry instruments. The actual core medical applications of peracetic acid are its potent antimicrobial action, also at low temperatures, and the total absence of toxic residuals.
Uses This microprocessor-controlled, low-temperature sterilization agent is a strong oxidizing disinfectant against a wide spectrum of antimicrobial activity. Peracetic acid is active against many microorganisms, such as gram-positive and -negative bacteria, fungi, spores, and yeast. This ideal antimicrobial agent is primarily used in food processing and handling as a sanitizer for food contact surfaces. Peracetic acid is also used to disinfect medical supplies and prevent biofilm formation in pulp industries. It can be applied during water purification as a disinfectant and for plumbing disinfection. Peracetic acid is suitable for disinfecting cooling tower water and effectively prevents biofilm formation and controls Legionella bacteria.
Terrestrial fate: If released to soil, peracetic acid has a very high mobility and exists partially in an anion form in the environment with a pKa of 8.2. Volatilization from moist soil surfaces is expected to be an important fate process. Aquatic fate: If released into water, peracetic acid hydrolyzes to acetic acid and hydrogen peroxide at pH values of 7–8 with the half-lives of 8 h. Atmospheric fate: If released to air, peracetic acid will exist exclusively as a vapor. The vapor will be degraded by reaction with photochemically produced hydroxyl radicals with a halflife of 9 days. Because of its high water solubility, peracetic acid can dissolve in clouds and rainwater and has been identified as a constituent of acid rain. Peracetic acid may also be susceptible to direct photolysis by sunlight, with chromophore absorption at wavelengths >290 nm.
Environmental persistency (degradation/speciation) Peracetic acid is formed naturally in the environment through a series of photochemical reactions involving formaldehyde and photo oxidant radicals. The pKa of peracetic acid is 8.2, indicating that this compound exists partially in anion form in the environment, and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. It degrades in the environment very quickly but has no potential to bioaccumulate. Its ultimate fate in the environment is in the basic molecules of carbon dioxide, oxygen, and water.
Long range transport Peracetic acid should be transported and stored in diluted solutions to prevent explosion.
Bioaccumulation and biomagnification An estimated BCF of 3 was calculated in fish for peracetic acid, using an estimated log Kow of 1.07 and a regression-derived equation. The BCF suggests that the potential for bioconcentration in aquatic organisms is low.
Exposure and Exposure Monitoring Environmental Fate and Behavior
Routes and pathways (including environmental release)
Routes and pathways, and relevant physicochemical properties (e.g., solubility, Pow, Henry constant,.)
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Peracetic acid production and usage as a disinfectant may result in its release through various waste streams or directly into the
Encyclopedia of Toxicology, Volume 3
http://dx.doi.org/10.1016/B978-0-12-386454-3.01197-0
Peracetic Acid
environment. The probable routes of peracetic acid are eye, dermal, inhalation, and ingestion.
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inflammation is characterized by itching, scaling, reddening, or occasionally blistering. Inflammation of the eyes is characterized by redness, watering, and itching.
Human exposure Occupational exposure to peracetic acid may occur through inhalation and dermal contact with this compound at workplaces where it is produced or used. Monitoring and use data indicate that the general population may be exposed to peracetic acid via ingestion of food and through dermal contact with products treated with peracetic acid.
Environmental exposure (monitoring data in air, water, sediment, soil, and biota) Peracetic acid is formed in the environment through a series of photochemical reactions involving formaldehyde and photo oxidant radicals. This compound’s high water solubility enables it to become a constituent in acid rain.
Toxicokinetics Peracetic acid is not readily absorbed into the circulatory system because of its high water solubility and its ability to form microbubbles in capillaries and tissues surrounding exposed tissues, but it is readily absorbed through skin damaged by the corrosivity of peracetic acid. Peracetic acid distribution throughout the body via physiological fluids may be limited by its degradation rate. Peracetic acid is degraded nonenzymatically by several ways via hydrolysis to hydrogen peroxide and water, a dismutation reaction in the presence of metal ions to acetic acid and water, or a reaction with reducing agents such as cysteine or glutathione, which convert peracetic acid to acetic acid.
Chronic Toxicity Prolonged exposure may result in skin burns and ulcerations. Overexposure by inhalation may cause respiratory irritation, including pulmonary edema and lung corrosion. Severe overexposure can result in death.
Genotoxicity The genotoxicity database for peracetic acid is limited and shows some conflicting results. In general, most bacterial mutagenicity tests were negative; however, peracetic acid is bactericidal, so the significance of these results is not clear. Two DNA repair tests in human fetal lung cells were also negative. In vitro tests were generally negative except for one positive result that was found at cytotoxic levels. Two mouse micronucleus studies were negative, as was in vivo/ex vivo assay of unscheduled DNA synthesis in rats exposed orally. Investigators reported positive results in a series of in vivo chromosomal aberration tests with single intraperitoneal and dermal administration; however, these studies were questionable owing to serious deficiencies in experimental protocol and reporting.
Carcinogenicity PAA is a potent tumor promoter and a weak carcinogen.
Clinical Management Mechanism of Toxicity Peracetic acid kills microorganisms by oxidation and subsequent disruption of their cell membrane via the hydroxyl radical. Because diffusion is slower than the half-life of the radical, it will react with any oxidizable compound in its vicinity. Peracetic acid, also, is not deactivated by catalase and peroxidase enzymes produced by microorganisms. Therefore, it can damage virtually all types of macromolecules associated with a microorganism, such as carbohydrates, nucleic acids, lipids, and amino acids. The mechanism of oxidation is the transfer of electrons; therefore, the stronger the oxidizer will produce faster and ultimately leads to cell lyse and true microbial death.
Because of the high self-reactivity rate of the substance, fire or other violent reactions may occur on contact with combustible organic material. If fire occurs in the vicinity of this compound, water should be used to keep containers cool. In advanced or massive fires, the area should be evacuated. Avoid breathing the vapors in a non-fire response. If ingestion occurs, do not induce vomiting or attempt to neutralize. Give victims water or milk only if they are conscious and alert. Children up to 1 year old, 125 ml (4 oz or 1/2 cup); children 1–12 years old, 200 ml (6 oz or 3/4 cup); adults, 250 ml (8 oz or 1 cup). If eye or skin exposure occurs, eyes must be flushed with lukewarm water for at least 15 min. Wash exposed skin areas thoroughly with soap and water. Under other advanced emergencies, transport victims to a health care facility.
Acute and Short-Term Toxicity The oral LD50 values of peracetic acid in mouse is 210 mg kg1, indicating that the acute toxicity experienced would be considered low. Dermal contact, eye contact, inhalation, and ingestion of peracetic acid are very hazardous. Concentrated peracetic acid is extremely corrosive to the skin. Skin
Ecotoxicology Freshwater/sediment toxicity of organisms The effect of PAA solutions on aquatic organisms occurred at concentrations higher than 1 mg l1. Fresh water species
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and crustaceans appeared more sensitive than salt water species. However, the development of mollusk larvae was found to be the most sensitive organism to the toxic effect of PAA. PAA is an active bactericide at levels >5 mg l1.
Exposure Standards and Guidelines In 2010, the United States Environmental Protection Agency published Acute Exposure Guidelines (AEGL) for peracetic acid.
Peracetic acid 79-21-0 10 min AEGL 1 AEGL 2 AEGL 3
30 min 3
0.52 mg m 1.6 mg m3 60 mg m3
60 min 3
0.52 mg m 1.6 mg m3 30 mg m3
4h 3
0.52 mg m 1.6 mg m3 15 mg m3
8h 3
0.52 mg m 1.6 mg m3 6.3 mg m3
0.52 mg m3 1.6 mg m3 4.1 mg m3
Toxicity to marine organisms PAA seems to be slightly toxic to Daphnia magna with the EC50 at 24 h is 116.6 mg l1.
See also: Peroxyacetic acid; Acetic Acid; Chloroacetic Acid.
Further Reading Toxicity to terrestrial organisms (soil microorganisms, plants, terrestrial invertebrates, terrestrial vertebrates) Phytotoxic effects found that 10 mg PAA/L in some growing vegetables, such as bean sprouts, and potato plants showered with up to 2000 mg l1 PAA did not show any change. However, cut or broken surfaces of vegetables were oxidized by PAA, resulting in discoloration and sometimes a change in texture.
Other Hazards Peracetic acid is an organic peroxide and explodes at 110 C. It should be transported and stored in diluted solutions to prevent explosion.
Hazardous Substances Data Bank, National Library of Medicine (HSDB), 2005. Peracetic acid (accessed 12.09.11). Natl. Toxicol. Program. Pohanish, R.P., 2002. Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, fourth ed. Noyes Publications, Norwich, NY.
Relevant Websites http://www.cdc.gov/hicpac/ – Peracetic acid sterilization (from Guideline for Disinfection and Sterilization in Healthcare Facilities 2008). http://cameochemical.noaa.gov/ – Peracetic acid (from Chemical Datasheet).