6.2 Product Knowledge & Chemistry: Water, pH & Nail Care Products
Key Takeaways
Water is the universal solvent. Only substances that contain water have a pH, and pure water is neutral at pH 7.
The pH scale runs 0–14. Below 7 is acidic, above 7 is alkaline, and it is logarithmic, so pH 9 is 100 times more alkaline than pH 7.
Cuticle removers are alkaline (about 2–5% sodium or potassium hydroxide with glycerin). Acid primers contain methacrylic acid. Skin's acid mantle is about pH 4.5–5.5.
Dehydrators remove surface moisture and oil. Adhesives and wrap resins are cyanoacrylates. Activators (accelerators) speed the cure of cyanoacrylate resin.
Base coat helps polish adhere and prevents staining. Top coat seals and protects the color. Non-acetone remover is gentler on artificial nails, while acetone dissolves polish and soak-off products fastest.
Quick Answer: Water is the universal solvent. pH measures how acidic or alkaline a water-based product is, on a 0–14 scale where 7 is neutral. Below 7 is acidic and above 7 is alkaline. The scale is logarithmic, so each whole number is a 10× change. Cuticle removers are alkaline (sodium or potassium hydroxide). Acid primers are acidic (methacrylic acid). Know the job of each product: remover dissolves polish, dehydrator removes surface oil and moisture, primer improves adhesion, adhesive and resin are cyanoacrylates, activator speeds resin cure, base coat anchors polish and prevents staining, and top coat seals.
Basic Chemistry Vocabulary
- Matter is anything that takes up space. Elements are the simplest substances, compounds are chemically joined elements, and mixtures are physically combined substances that keep their own properties.
- A physical change alters form without making a new substance, as when water freezes or polish solvent evaporates. A chemical change makes a new substance, as when monomer polymerizes into acrylic or gel cures.
- Exothermic reactions give off heat. Monomer polymerizing and gel curing are exothermic, which is why thick layers can cause a burning "heat spike."
Mixtures in nail products:
| Type | Definition | Example |
|---|---|---|
| Solution | A stable, even mixture of a solute dissolved in a solvent. It does not separate | Diluted disinfectant; acetone remover |
| Suspension | An unstable mixture of undissolved particles that separate on standing, so you shake before use | Nail polish, where pigments settle and a mixing ball helps |
| Emulsion | An unstable mixture of two immiscible liquids, such as oil and water, held together by an emulsifier (surfactant) | Hand lotions, massage creams |
Miscible liquids mix, like water and alcohol. Immiscible ones don't, like water and oil. Surfactants (surface-active agents) let oil and water mix. They are what make soaps and detergents clean.
Water
Water is the most abundant compound on Earth and is called the universal solvent because it dissolves more substances than any other liquid. In the salon:
- Potable water is safe to drink. Kansas requires establishments to have hot and cold running potable water (K.A.R. 28-24-13(d)), and implements and pedicure equipment are rinsed with potable water after disinfecting.
- Disinfectant concentrates are diluted with water in measured amounts. The ratio on the label is what makes the product work.
- Too much water in the nail plate from long soaking makes the plate swell and can shorten polish wear (section 8.2).
The pH Scale
pH ("potential hydrogen") describes the balance of hydrogen and hydroxide ions in a water solution.
| pH | Meaning | Examples in nail care |
|---|---|---|
| 0–6.9 | Acidic | Acid primer (methacrylic acid); alpha hydroxy acid scrubs; skin's acid mantle (about 4.5–5.5) |
| 7 | Neutral | Pure water |
| 7.1–14 | Alkaline (basic) | Cuticle removers and callus softeners (sodium or potassium hydroxide); many soaps |
Key facts:
- The scale is logarithmic. pH 8 is 10 times more alkaline than pH 7, and pH 9 is 100 times more alkaline than pH 7.
- Only substances that contain water have a pH. Pure acetone or oil has no pH.
- Acids and alkalis neutralize each other. Rinsing an alkaline cuticle remover thoroughly, and using acid-balanced products afterward, helps restore the skin's natural acidity.
- Strong products at either end of the scale can burn skin. That is why cuticle remover stays on the nail plate and off the skin, and acid primer is applied in tiny amounts.
Nail Care Products NTN Lists
| Product | What it is and does | Safety notes |
|---|---|---|
| Polish remover | Solvent that dissolves polish. Acetone removers work fastest. Non-acetone removers (often ethyl acetate) are gentler on tips, wraps and other enhancements | Flammable. Drying to skin. Keep capped |
| Cuticle remover | Alkaline product, typically 2–5% sodium or potassium hydroxide with glycerin, that loosens dead cuticle tissue on the nail plate | Apply to the nail plate. Avoid prolonged skin contact. Rinse or remove thoroughly |
| Nail conditioner | Moisturizing product, such as oils, creams or conditioning treatments, that helps prevent brittle, dry nails and cuticles | Good for daily home care |
| Nail hardener | Product that strengthens nails. Protein types coat the nail. Formaldehyde types cross-link keratin | Formaldehyde hardeners can cause allergic reactions and overly brittle nails. Keep off skin |
| Base coat | First coat under polish. Creates a sticky surface for adhesion and prevents staining of the natural nail | Apply thinly. Cap the free edge |
| Nail polish | A suspension of a film former (nitrocellulose), resins, plasticizers, solvents and pigments | Flammable. Roll the bottle gently rather than shaking hard, to avoid bubbles |
| Top coat | Clear coat that seals and protects the color, adds shine and resists chipping | Cap the free edge |
| Nail adhesive | Cyanoacrylate glue that bonds tips and repairs | Bonds skin instantly. Don't apply with cotton, which can react and give off heat |
| Dehydrator | Temporarily removes surface moisture and oil from the natural nail before enhancements or polish (often isopropyl alcohol or a similar solvent) | Flammable. Nail plate only |
| Activator (accelerator) | Speeds the hardening of cyanoacrylate wrap resin and dip systems, by spray, brush or drop | Hold spray at the manufacturer's distance. Too close can cause heat on the nail |
| Monomer liquid | Liquid (usually ethyl methacrylate, EMA) that combines with polymer powder to form acrylic enhancements | Vapors. Skin sensitizer. MMA is prohibited |
| Polymer powder | Powder of pre-formed polymer beads that contains the initiator benzoyl peroxide | Keep the container closed. Take out only one client's portion |
| Primer | Improves adhesion of enhancement product to the natural nail. Acid-based primer (methacrylic acid) etches and dries chalky. Acid-free primer bonds chemically | Acid primer is corrosive. Use a tiny amount, nail plate only, with eye protection |
Reading a Product Correctly
- Read the label first and keep the SDS handy (section 5.2).
- Use each product only for its intended purpose. A cuticle remover is not a callus softener unless its label says so.
- Keep every product in a labeled, closed container (K.A.R. 28-24-6). Label secondary containers.
- Dispense without contaminating the unused portion, and discard what you took out but didn't use.
On the pH scale, how does a product with a pH of 9 compare with one at pH 7?
It is 2 times more alkaline
It is 20 times more acidic
It is 100 times more alkaline
It is exactly neutral, because pH 7 through 9 is the neutral range
What is the main chemical characteristic of a typical cuticle remover?
It is alkaline, commonly containing about 2–5% sodium or potassium hydroxide
It is strongly acidic, containing methacrylic acid
It is neutral water with fragrance
It is a cyanoacrylate that hardens the cuticle so it can be clipped
Which product is used to speed up the hardening of cyanoacrylate wrap resin?
Dehydrator
Primer
Base coat
Activator (accelerator)
Why does a nail technician apply base coat before polish?
To dissolve old polish residue
To help the polish adhere and to prevent staining of the natural nail
To speed the drying of the top coat
To soften the cuticle before pushing
Sections you finish are checked off in the contents.