September 18, 2023

Unveiling the Power of Muriatic Acid: Properties, Uses, and Precautions

What is muriatic acid?

Muriatic acid is an aqueous solution of hydrogen chloride containing the chemical formula HCl. The colorless solution features a distinctive pungent smell. Although Muriatic acid is corrosive, it helps remove mold, stains, and rust from different surfaces, including brick, concrete stone, and swimming pools. 

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Dilute it with water before you use it. Hydrochloric acid was first discovered around 800 C.E. by the alchemist Jabir ibn Hayyan (Geber) mixing salt with sulfuric acid. This article will take you through its chemical composition, applications, uses, and alternatives. 

Chemical Composition and Properties

Chemical Formula and Structure

It is a compound of hydrogen and chlorine, a gas at room temperature and pressure. The chemical formula for muriatic acid is HCl. It is an aqueous solution of a gas known as hydrogen chloride. 

Concentration and pH Levels

Muriatic acid is a pH reducer and liquid acid with a pH of less than two at the 31.45 per cent concentration. Muriatic acid diluted to between 14.5 and 29 per cent.

Corrosive Nature and Reactivity

Muriatic acid is a corrosive substance that can dissolve iron, and it violently reacts with other metals, like aluminum and magnesium, and bases, like sodium hydroxide. These reactions are highly exothermic and release more heat energy during the process. The aqueous hydrogen chloride solution is highly corrosive. 

Production and Sources

Industrial Synthesis Methods

Hydrochloric acid is prepared industrially by dissolving hydrogen chloride in water. Hydrogen chloride can be generated in many ways, resulting in several precursors to hydrochloric acid.

Natural Sources and Occurrence

Muriatic acid is from minerals and petroleum. Get it from home improvement stores because of its use in multiple heavy-duty tasks, such as salt deposits. 

Industrial Applications

Metal Cleaning and Surface Preparation

Brush the acid on at a 1:10 acid/water dilution and scrub with a nylon brush. Remove rust, neutralize the acid with a baking soda-water paste, and apply the paste. Ensure it thoroughly coats acid-washed, let sit for 10 minutes, and then rinse with water, dry, and prep for paint.

pH Regulation in Industrial Processes

Muriatic acid controls industrial wastewater pH and cleans commercial pool plasters and masonry. It is there to purify and adjust the pH of brine before chlor-alkali production.

Pickling and Galvanizing

The pickling time in hydrochloric acid is much faster at 25 C but longer than sulfuric acid at elevated temperatures (  Add it to a spray bottle or apply directly onto the galvanized metal. It starts eating away at the shiny coating very fast. Use a rag to wipe around the Muriatic Acid. Expect the metal to lose its shine quickly.

Household Uses

Swimming Pool Maintenance

Muriatic acid is there to make sure that water chemistry is maintained. Adding muriatic acid into pool water helps reduce pH levels that have become too high.

Cleaning Masonry and Concrete Surfaces

It also kills mold and mildew on hard surfaces like brick, tile, concrete, and stone. Mix one part muriatic acid to eight parts water, then spray or brush the solution onto the moldy area. Give it a few minutes, scrub it with a nylon brush, and rinse the area well with clean water.

Rust Removal and Household Cleaning

Put on gloves, goggles, and protective clothing before you start working. Dilute the muriatic acid solution with the water.  Always pour acid into water, brush the acid on the rust, and scrub with a scrub brush until the rust is gone. 

Safety Measures and Handling

Personal Protective Equipment (PPE)

  • Wear rubber gloves and eye protection when handling. 
  • Goggles work as vapor proof. 
  • Wash hands after handling. 
  • Give ventilation for storage and use areas

Proper Ventilation and Storage

Store muriatic acid in a cool, dry place with enough ventilation to protect the acid from the toxicity of vapors. Keep it away from chemicals that it can react with. 

First Aid and Emergency Response

Get medical attention immediately in case of contact. Immediately flush skin with water for at least 15 minutes while removing contaminated clothing and shoes. Also, wash clothing before reuse.

Environmental Impact

Effects on Water Bodies and Aquatic Life

Hydrochloric acid can be toxic to aquatic life by reducing aqueous pH to toxic levels. Since aquatic species are intolerant of pH levels lower than 5.5 for any extended length of time, the acid will be a problem.

Air Quality and Emissions

In the event of a spill, keep the spill from contaminated soil, surface, or groundwater. Muriatic acid can decrease the pH of soil or water. Hydrogen chloride released into the atmosphere as a gas will undergo wet and dry deposition, and be incorporated into clouds or rain.

Alternatives to Muriatic Acid

Vinegar and Citric Acid

Citric acid and vinegar are both acids, but citric acid is a mild reducing agent. It can do chemistry with acetic acid. Vinegar is a weak form of ACETIC ACID, whereas Muriatic acid is a diluted form of HYDROCHLORIC ACID. Vinegar will take 10X – 20X as long to remove mill-scale as Muriatic Acid. 

Commercial Non-Acidic Cleaners

Trisodium phosphate is another alternative to muriatic acid. It cleans masonry in much the same way as muriatic acid. Trisodium phosphate is a heavy-duty cleaning agent with the same dangers as muriatic acid.

Benefits and Drawbacks

Effective Cleaning and Descaling

Muriatic Acid works in industrial water treatment, de-mineralizing boilers, descaling dish machines, and hard surfaces where lime and calcium buildup is problematic. It is an effective rust and stain remover.

Potential Hazards and Risks

Muriatic acid is harmful if swallowed and may lead to irreversible damage to mucous membranes. Prolonged exposure to corrosive materials or fumes may cause gastrointestinal disturbances.

Precautions for Home Users

Dilution Guidelines

The degree of dilution varies depending on the job. The formula is one-part muriatic acid to 10-part water. When diluting, pour the acid into the water slowly and carefully. Never add water to acid to avoid an exothermic reaction, propelling the acid out of the container and onto you.

Appropriate Surfaces and Materials

For better results, apply diluted muriatic acid on tiled and concrete surfaces. This solution best suits swimming pool surfaces. Muriatic acid works wonders when removing rust from stainless steel.

Disposal Regulations

Instead of throwing it away, use leftover muriatic acid to clean brick, concrete, toilets, and tile. Use it to balance your pool’s pH or give leftover muriatic acid to a local hazardous waste facility. They will dispose of it for you. Do not pour muriatic acid outside or down a storm drain.

Muriatic Acid in Art and Restoration

Etching and Patination

Muriatic acid is applied to the surface of a piece of metal to create an image, design, or component. Acid etching does not change the properties of a metal.

Historic Restoration Projects

The acid removes exterior dirt, paint, stains, and Graffiti from historic masonry buildings.

Medical and Pharmaceutical Uses

pH Adjustment in Medical Settings

It neutralizes alkalinity and creates carbon dioxide, which lowers pH levels and balances the water. If the water in your pool becomes too basic or alkaline, use hydrochloric acid to lower the pH.

Chemical Synthesis in Pharmaceuticals

The pharmaceutical industry uses muriatic acid as a catalyst, chemical reactant, pH control, water treatment, and reducing agent for pharmaceutical ingredients.

Research and Innovations

Sustainable Production Methods

The method that produces high-purity PA, no waste, and provides added value for other CRMs may include metals. Acid leaching using hydrochloric acid (HCl), offers high metal solubility and enhanced redox potentials.

Green Chemistry Initiatives

Green chemistry seeks to design and produce cost-competitive chemical products like muriatic acid and processes that attain the highest level of the pollution-prevention hierarchy by reducing pollution at its source.

Case Studies

Muriatic Acid in Industrial Processes

In Industrial Processes, muriatic acid is used for food processing, oil and gas acidizing, chemical production, and steel pickling.

Successful Applications and Lessons Learned

Muriatic acid is an effective cleaning agent that should not mix with chemicals like bleach or potassium permanganate. Apply the acid with a throwaway brush to keep it confined and not run down over your work.

Muriatic Acid in DIY Projects

Crafting and Home Improvement

Muriatic acid removes stains, mold in basements, stains, and mold from tiled or concrete swimming pool surfaces. It is also for cleaning seashells.

Precautions and Creative Applications

Wear full-face protection, a respirator, thick, full-coverage clothing, and acid-resistant protective gloves when using muriatic acid. Muriatic acid must be diluted in water.

Summary of Benefits

Muriatic acid is versatile, considering its multi-industry applications. Its applications include pH adjustment in water treatment, pickling and cleaning of metals, and chemicals like chlorides and other compounds. It also works in the food industry for processing and household cleaning products. It is cost-effective and efficient. 

Potential Risks and Challenges

Corrosion and Health Hazards

Acute oral exposure may lead to corrosion of mucous membranes, esophagus, and stomach, with nausea, vomiting, and diarrhea. Skin contact causes severe burns, repeated or dermatitis.

Environmental Concerns

Keep Muriatic acid out of lakes, streams, ponds, or other water sources. Take precautions to minimize potential harm to people, animals, and the environment.

FAQs about Muriatic Acid

Is muriatic acid the same as hydrochloric acid?

Yes, muriatic acid and hydrochloric acid are the same substance. “Muriatic acid” is a common name used in various industries and applications, while “hydrochloric acid” is its chemical name. Both terms refer to the same highly acidic solution used for cleaning, etching, and pH adjustment in industrial and household settings.

Can muriatic acid be used for descaling kitchen appliances?

Muriatic acid, or hydrochloric acid, is highly corrosive and hazardous. It’s not recommended for kitchen appliances like coffee makers, kettles, or dishwashers. These appliances need milder, food-safe descaling solutions. Using muriatic acid in them risks health issues, appliance damage, and food contamination. Follow manufacturer recommendations for safe, appliance-specific descaling products. Prioritize safety and adhere to usage guidelines when handling chemicals like muriatic acid.

How should I store muriatic acid at home?

When storing muriatic acid at home, follow these safety guidelines:

  • Select a Suitable Location: Choose a well-ventilated, cool, dry area away from direct sunlight, avoiding extreme temperatures.
  • Use a Chemical Storage Cabinet: Preferably, use a cabinet designed for corrosive materials with proper ventilation.
  • Keep Away from Incompatible Materials: Store away from ammonia, bleach, or flammable substances to prevent reactions.
  • Secure Containers Properly: Ensure acid remains in its sealed, compatible container, labeled with content and hazard details.
  • Elevate Containers: Place containers on raised surfaces to prevent spills from reaching the floor.
  • Maintain Proper Ventilation: Ensure good airflow and consider using an exhaust fan in the storage area.
  • Separate from Incompatible Chemicals: Store muriatic acid separately from other chemicals.
  • Childproofing: If kids or pets are present, lock acid away, out of reach, and sight.
  • Emergency Equipment: Keep eyewash station and spill kit nearby for accidents.
  • Read the Label: Consult the manufacturer’s instructions on the label for storage and safety specifics.

Remember, muriatic acid is highly corrosive and mishandling can cause accidents. Following these guidelines and manufacturer recommendations ensures safe home storage.

What safety gear is necessary when handling muriatic acid?

When handling muriatic acid, prioritize safety with these measures:

  • Acid-Resistant Gloves: Use neoprene, nitrile, or rubber gloves to shield your hands completely from corrosive acid.
  • Eye Protection: Wear safety goggles or a full-face shield to guard against splashes or fumes.
  • Respirator or Mask: Based on acid concentration and ventilation, consider a respirator or mask with acid-resistant filters, certified for chemical protection.
  • Protective Clothing: Don acid-resistant attire, including a lab coat or chemical-resistant suit, long pants, and a long-sleeved shirt. Avoid materials that acid can penetrate, like cotton.
  • Closed-Toe Shoes: Opt for acid-resistant, closed-toe, non-slip footwear. Avoid sandals or materials sensitive to acid.
  • Ventilation: Ensure good ventilation or use a fume hood indoors to disperse harmful fumes when working with muriatic acid.
  • Emergency Equipment: Know the location and use of emergency eyewash stations, safety showers, and spill kits for accidents or spills.
  • Personal Hygiene: Don’t drink or smoke while handling muriatic acid. Wash hands thoroughly after, avoiding face contact or eating.
  • Emergency Response: Understand acid spill and exposure procedures. For larger spills or accidents, contact emergency services immediately.

Muriatic acid is highly corrosive and hazardous. Prioritize safety, and follow manufacturer instructions for proper use and storage.

Are there any eco-friendly alternatives to muriatic acid?

There are eco-friendly alternatives to muriatic acid for various cleaning and surface treatments. Premier Eco Acid Wash is one such option. Keep in mind that product availability varies by location. Here are some alternatives:

  • Vinegar: A common household item, vinegar is a milder acid substitute for cleaning and descaling. It effectively removes mineral deposits and rust.
  • Citric Acid: Derived from citrus fruits, it’s biodegradable and can be used for descaling appliances, rust removal, and surface cleaning.
  • Baking Soda: When mixed with water or lemon juice, it creates a gentle abrasive cleaner for various surfaces.
  • Bio-based Cleaners: Look for certified eco-friendly products from organizations like Green Seal or EcoLogo, designed to be less environmentally harmful.
  • Oxygen Bleach: This, like hydrogen peroxide-based products, can remove stains, whiten surfaces, and clean without traditional bleach’s harshness.
  • Enzyme Cleaners: Effective in breaking down organic stains and odors, making them suitable for specific cleaning tasks.
  • Steam Cleaning: Ideal for removing grime and cleaning floors, it’s an eco-friendly option as it solely uses water and heat.

Choose an eco-friendly alternative based on your specific task and surface, while considering environmental and safety concerns. Always follow product instructions and safety guidelines for effective and safe use.


Muriatic acid is a cleaning agent, but a dangerous product. Use it with caution when cleaning. It is suitable for almost any job involving a stone wall, patio, terrain step, or other hardscape made of mortar or concrete. Follow the tips above to achieve better results and ensure safety. Be responsible enough to use the acid to clean water or household items instead of throwing the acid away.

David D. Hughes

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