DIY cosmetics
What's safe to make
Lip balms (waxes+oils), scrubs (sugar+oil), solid shampoos, hydrosol toners. Anhydrous products keep for months without preservatives.
Water-based recipes
Creams and lotions with water WITHOUT preservative — max a week in the fridge. Natural ≠ safe: essential oils — 0.5–2% dosing, citrus phototoxicity.
pH and actives
Acids (AHA/BHA, vitamin C) need pH control at 3–4 — useless without strips/meter. Niacinamide 2–5% is compatible with almost everything.
Allergy testing
Patch test on the inner elbow 24–48h before every new recipe. Top allergens: essential oils, fragrances, MIT preservatives.
Production hygiene
70% alcohol on surfaces and tools, distilled water, clean jars. A preservative dosing error = mold within a week.
Selling = regulation
Cosmetics for sale — certification, declaration of conformity, INCI labeling. 'For myself' and 'for sale' are different legal worlds.
Reference material only. Recipes are not medical advice — consult a dermatologist for skin conditions.
About DIY cosmetics
DIY cosmetics — safe recipes: preservatives, pH, patch tests. Chemistry & Lab: Molar mass, dilution, pH, gases, safety. Use our tools without registration or installing software. All calculations happen in your browser — your data is never sent to a server.