Product Chemistry and Safe Use of Cosmetics
Chemistry items are where candidates lose easy marks: the exam asks why a product burns, why a long-time client suddenly reacts, and what the label and SDS actually require.
Product families
- Solvents: acetone, ethyl acetate and isopropyl alcohol dissolve polish and resin, defat skin and evaporate quickly.
- Monomers and polymers: EMA monomer with polymer powder; acrylate gels with photoinitiators that react to UV or LED light.
- Adhesives: cyanoacrylate, which polymerizes with moisture and bonds skin on contact.
- Oxidizers and pH adjusters: hydrogen peroxide, persulfates and acids or bases in cleansers.
- Additives: plasticizers, pigments, preservatives and fragrance.
Why reactions happen
Acrylates are sensitizers. Repeated skin contact can produce allergic contact dermatitis, with itching, redness and small blisters that may appear away from the application site, and sensitization is permanent. Uncured gel on skin, aerosolized monomer and over-filed plates raise risk. Over-filing and trapped solvent under an enhancement cause onycholysis. Mixing brands of liquid and powder can block cure and irritate skin.
Controls and labels
The SDS gives hazards, first aid and storage. Keep lids on, use a covered monomer dish, ventilate, wear nitrile gloves because latex resists acrylates poorly, and wear eye protection when pouring. Never decant into unlabeled bottles, store away from heat and flame, and never seal solvent-soaked waste in a closed bin.
Worked example
A client reports itching and tiny blisters on her eyelids three days after a gel manicure. Reasoning: eyelid dermatitis after nail work is a classic acrylate allergy from touching the face with uncured product on the hands. It is not coincidence, not contagious, and not solved by switching to another acrylate brand. Remove the product, advise a physician or patch testing, record the reaction, and offer non-acrylate services afterward.
Traps
Assuming a product is safe because it does not burn; expecting sensitization to fade; substituting one acrylate for another; and using acetone near the eyes or on broken skin.