chemistry

Peracetic acid

Peracetic acid is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Peracetic acid rather than just read about it. In short: Peracetic acid (also known as peroxyacetic acid, or Percidine) is an organic compound with the formula CH3CO3H. This peroxy acid is a colorless liquid with a characteristic acrid odor reminiscent of acetic acid.

Key takeaways

Peracetic acid belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Peracetic acid to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Peracetic acid from memory before moving on to harder problems.

Reference excerpt

Peracetic acid (also known as peroxyacetic acid, or Percidine) is an organic compound with the formula CH3CO3H. This peroxy acid is a colorless liquid with a characteristic acrid odor reminiscent of acetic acid. It can be highly corrosive. Peracetic acid is a weaker acid than the parent acetic acid, with a pKa of 8.2.

Production Peracetic acid is produced industrially by the autoxidation of acetaldehyde:

O2 + CH3CHO → CH3CO3H Peracetic acid is conventionally prepared by combining acetic acid and hydrogen peroxide with homogeneous acid catalysts (e.g., sulfuric acid), which facilitate the reaction and achieve equilibrium between the reagents and product:

H2O2 + CH3CO2H ⇌ CH3CO3H + H2O While it is feasible to create peracetic acid by combining consumer-grade vinegar (5% acetic acid) and hydrogen peroxide (3%) without an acid catalyst, the low concentration of reagents will result in a slow reaction rate at room temperature. Extrapolating from published reaction rates, the time to equilibrium is estimated to be on the order of weeks. As an alternative, acetyl chloride and acetic anhydride can be used to generate a solution of the acid with lower water content. Peracetic acid is also generated in situ by some laundry detergents. This is achieved by the action of bleach activators, such as tetraacetylethylenediamine and sodium nonanoyloxybenzenesulfonate, upon hydrogen peroxide formed from sodium percarbonate in water. The peracetic acid is a more effective bleaching agent than hydrogen peroxide itself. PAA is also formed naturally in the environment through a series of photochemical reactions involving formaldehyde and photo-oxidant radicals. Peracetic acid is always sold in solution as a mixture with acetic acid and hydrogen peroxide to maintain its stability. The concentration of the acid as the active ingredient can vary.

Uses The United States Environmental Protection Agency first registered peracetic acid as an antimicrobial in 1986 for indoor use on hard surfaces. Use sites include agricultural premises, food establishments, medical facilities, and home bathrooms. Peracetic acid is also registered for use in dairy and cheese processing plants, on food processing equipment, and in pasteurizers in breweries, wineries, and beverage plants. It is also applied for the disinfection of medical supplies, to prevent biofilm formation in pulp industries, and as a water purifier and disinfectant. Peracetic acid can be used as a cooling tower water disinfectant, where it prevents biofilm formation and effectively controls Legionella bacteria. Nu-Cidex is the trade name for a brand of antimicrobial peracetic acid. In the European Union, peroxyacetic acid was reported by the EFSA after submission in 2013 by the US Department of Agriculture. Decontamination kits for cleaning fentanyl analogues from surfaces (as used by many police forces, amongst others) often contain solid peracetyl borate, which mixes with water to produce peracetic acid.

Epoxidation Although less active than more acidic peracids (e.g., m-CPBA), peracetic acid in various forms is used for the epoxidation of various alkenes (Prilezhaev reaction). Useful applications are for unsaturated fats, synthetic and natural rubbers, and some natural products such as pinene. A variety of factors affect the amount of free acid or sulfuric acid (used to prepare the peracid).

Safety Peracetic acid is a strong oxidizing agent and severe irritant to the eyes, skin, and respiratory system. The U.S. Environmental Protection Agency published the following Acute Exposure Guideline Levels (AEGL):

See also Diacetyl peroxide Disinfectant Hydroxyl Organic peroxide Peroxy acid Trifluoroperacetic acid

References

Illustrations

Worked examples

Example 1 — a first encounter with Peracetic acid

Start with the simplest possible case. Write down what Peracetic acid claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Peracetic acid before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Peracetic acid ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Peracetic acid

In research: Peracetic acid appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Peracetic acid in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Peracetic acid is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bleaches, Disinfectants, Foul-smelling chemicals, so understanding it makes those chapters shorter.
In everyday life: Look for Peracetic acid outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Peracetic acid in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Peracetic acid means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Peracetic acid out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Peracetic acid in simple terms?

Why does Peracetic acid matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Peracetic acid?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Peracetic acid.