Chemistry, Product Knowledge, and Electricity
pH and solutions
The pH scale runs 0–14; skin's acid mantle is about 4.5–5.5. Acids lower pH, bases raise it, and neutralization moves a solution toward 7. Products are solutions, suspensions, or emulsions (oil plus water held together by an emulsifier).
Ingredient functions
- Surfactants clean - one end loves water, the other loves oil.
- Humectants attract water (glycerin, hyaluronic acid).
- Emollients soften and smooth (oils, esters).
- Occlusives seal in moisture (petrolatum, dimethicone).
- Antioxidants (vitamins C and E) prevent oxidation and protect.
- Preservatives prevent microbial growth and are essential in any water-containing product.
Electricity
- Volt = electrical pressure; amp = current flow; ohm = resistance; watt = power.
- Direct current (galvanic): flows one direction. The cathode (negative) is alkaline and softens sebum (desincrustation); the anode (positive) is acidic (iontophoresis).
- Alternating current: high-frequency/Tesla current produces violet sparks and is drying and germicidal.
- Avoid electrical devices for clients with pacemakers, pregnancy, epilepsy, metal implants, or heart conditions.
Traps
- Galvanic is direct; high frequency is alternating.
- Do not confuse amps with volts.
- "Natural" does not mean safe or preserved; water-based products without preservatives grow microbes.
Rule of thumb: "Volt pushes, amp flows, ohm resists - and galvanic is direct while Tesla alternates."