Intro to PAA
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Peracetic Acid Makeup
Peracetic acid is an organic chemical compound that is produced from acetic acid (main ingredient in vinegar) and hydrogen peroxide. The acetic acid and oxygen sources are used in highly concentrated forms to produce the final peracetic acid product in sufficient concentration for commercial use. The acetic acid is normally in the glacial form (water free) and is nearly 100% concentration compared to the typical 5% in vinegar. The oxygen is obtained from hydrogen peroxide normally at 50% concentration compared to the 3% medical strength typically found in household product. The structural representation of peracetic acid is shown below; it is the peroxide group ―O―O― that gives peracetic acid its important strong oxidizing characteristics.
In contemporary thinking, peracetic acid may be thought of as an oxidizer as it contains extra available oxygen. Here, the term available oxygen means that the oxygen is highly reactive toward other materials. The performance of peracetic acid during disinfection and bleaching applications (just to name a couple) is far greater than either acetic acid or hydrogen peroxide used separately or together.
The name peracetic acid is the most common. Since its first synthesis in the late 1800’s, it has acquired dozens of synonyms, some of which are mentioned here:
| peracetic acid | peracid | acetylhydroperoxide |
| peroxyacetic acid | peroxy acid | monoperacetic acid |
| PAA | ethaneperoxyacid | acetic peroxide |
The name under IUPAC (International Union Of Pure And Applied Chemistry, est. 1919) nomenclature rules is ethaneperoxic acid.
Forms of PAA
Equilibrium Peracetic Acid is a general term for a mixture of peracetic acid "in equilibrium" with its starting materials, plus sulfuric acid catalyst. The catalyst must be present to produce the final peracetic acid product within a reasonable time and in sufficient concentration for practical use. It is a characteristic of this particular equilibrium that there is more unused hydrogen peroxide and unused acetic acid than the active finished product. The structural representations of equilibrium peracetic acid solutions are represented here:
Peragen® Aqueous (or Distilled) Peracetic Acid, also represented as aq‑PAA™, contains only peracetic acid and water (with only trace levels of the starting materials). The structures of the aq‑PAA™ solution are represented as:
When comparing the "aqueous" PAA to "equilibrium" PAA solutions, it is obvious that the Peragen® aq‑PAA™ contains substantially less chemical ingredients and nearly 100% conversion to peracetic acid.