Acetic acid, also known as methane carboxylic acid and ethanoic acid, is a colorless liquid, which has a strong and pungent smell. Most of us are familiar with the mild appearance of this chemical compound as a sour-tasting food additive liquid that we call vinegar, which is just ethanoic acid diluted in water. For thousands of years, acetic acid was only made biologically by microbes called acetic acid bacteria. Today, acetic acid is an important industrial chemical manufactured artificially in labs, and it is even used as a raw material in the synthesis of other chemical compounds. Acetic acid is a weak, colorless, caustic, and flammable acid with a sour taste and a strong smell. Liquid acetic acid is a hydrophilic polar protic solvent just like water and ethanol. It does not only dissolves ionic salts and sugars but also non-polar compounds such as oils as well as polar solutes. Acetic acid is a feedstock chemical reagent for the production of several other chemical compounds used industrially and domestically. In the industrial sector, the large-scale application of acetic acid is in the production of vinyl acetate monomer, followed by acetic anhydride and ester production. Apart from industrial purposes, acetic acid can be used for several domestic purposes also.
Uses of Acetic Acid
Acetic acid is one of the few elements that have a variety of applications ranging from culinary arts to industrial manufacturing. Let’s take a look at few uses of acetic acid in 0ur daily life.
In our daily life, we come across one of the most common uses of ethanoic acid as vinegar, where it exists around 5% in concentration. When it comes to cooking, vinegar is more than just an ingredient in recipes. It can perform marvelous functions ranging from improving flavor, preserving food, filling in for missing ingredients, and even making food look better. Although vinegar is mostly used as a food ingredient, its acidic properties also make it useful for cleaning and several other purposes. Acetic acid is considered a type of weak acid that has an extremely low pH value; however, it doesn’t completely dissociate in water. In baking, acetic acid reacts with alkaline leavening chemicals that produce carbon dioxide gas bubbles. This not only results in the tenderness and structural support of baked foods, but it also provides a tangy flavor to them.
When it comes to wiping off stubborn stains, acids are typical chemicals because of their reactivity towards other chemicals. While many strong acids are used industrially to remove mineral deposits, rust stains, and wipe off other chemicals, a weak acid like acetic acid can also be used domestically in low concentrations to get rid of coffee marks, rust stains, and even oils from the glassware, metal, and wooden surfaces. In fact, several aqueous solutions of acetic acid are sold commercially as a household cleaner with acetic acid concentrations ranging up to 50%. Moreover, vinegar, being a natural disinfectant, can also be used as a disinfectant to clean countertops in the kitchen, bathroom, or lavatories; however, acetic acid or vinegar must not be used to clean off marble and granite surfaces as it may induce a chemical reaction.
For more than 6000 years, acetic acid has been employed in medical applications because of its antimicrobial properties. In the pharmaceutical industry, acetic acid is widely used as an intermediate chemical in the manufacturing of several active pharmaceutical ingredients. It has been shown to have good antibacterial activity against micro-organisms such as planktonic organisms and pathogenic bacterias. A diluted solution of vinegar has an excellent bactericidal effect, and therefore, seems to be suitable as a first aid antiseptic for open wounds. Moreover, it is quite evident from the use of vinegar as a preservative that it is efficient in stopping the growth of bacteria. A solution of 0.25% acetic acid is used to prevent the growth and proliferation of susceptible urinary pathogens (especially ammonia-forming bacteria) associated with prolonged use of an indwelling urethral catheter. In medical diagnosis, acetic acid may also be applied to the cervix in screening for cervix cancer. Acetic acid otic is also used in the treatment of bacterial or fungal infection; however, the procedure is not recommended for people with damaged air drums as it may cause medical complications. Another trivial use of acetic acid in the medical sector is in the treatment of warts and burn wounds.
Besides being an effective disinfectant, acetic acid is also an excellent herbicide for domestic use. Although it can not be employed on a large scale to get rid of weeds from crops, acetic acid can be used as a cheap alternative for weedicides in gardening. The effectiveness of acetic acid as a herbicide, however, is subjected to the type of weed, its age, and the concentration of acetic acid used in the process. It is important to keep the concentration of acetic acid under control as it may cause environmental damage. Also, the equipment chosen for the spray should have a small nozzle so that it may not cause any unwanted damage. Being acidic in nature, acetic acid may lower the pH value of soil; however, the effects are temporary as acetic acid breaks down quickly in water. Furthermore, the pungent odor of acetic acid also keeps away ants and other insects from destroying the floral plants.
Acetic acid is a commodity chemical with the demand of several million tons per year in the polymer industry. A substantial amount of acetic acid production goes into the manufacturing of vinyl acetate monomer that can be polymerized to polyvinyl acetate or other polymers. These polymers are commonly found in several products such as paints, inks, dyes, and adhesives. Another important use of acetic acid in the polymer industry is the production of cellulose acetate (a synthetic textile and a bioplastic that is used in photographic films). Acetic acid is also utilized as a solvent in the production of terephthalic acid, which is then employed as a precursor in polyethylene terephthalate (PET) production. PET is a thermoplastic polymer used to make water bottles, microwave-safe containers, packing trays, cosmetic jars, etc.
Although concentrated acetic acid is hazardous for the skin, it is widely used in the cosmetic industry to lower the pH of ingredients. Acetic acid is used in the formulation of hair conditioners, shampoos, hair rinses, wave sets, and other hair care products. Alkyl acetates, as well as acetic acid and acetate salts, are common cosmetic chemicals that serve a variety of purposes as perfumes, solvents, or skin conditioners, depending on the substance. Moreover, the antibacterial and antifungal properties of acetic acid also play a beneficial role in cosmetics and personal care products. A diluted solution of apple cider vinegar is considered an effective facial cleanser to get rid of oil, dirt, and other pollutants.
Despite its many benefits, ethanoic acid in higher concentrations can cause health hazards, and therefore, it must be handled carefully. When working with concentrated ethanoic acid, it is recommended to wear protective clothing and eyewear at all times. Also, the workplaces must be well ventilated, and respiratory protection should be ensured. Highly concentrated acetic acid can damage the cornea of the eye as well, and that can result in vision loss.