Cosmetic Preservatives

— A Guide for Skincare Formulators

Preservatives are the backbone of safe skincare formulation. They protect your products from bacteria, mold, yeast, and oxidation, ensuring they remain safe, stable, and effective throughout their shelf life.

Whether you're formulating creams, gels, lotions, floral waters, face packs, scrubs, serums, or balms, choosing the correct preservative depends on:

• Product Format (Water-based, Oil-based, or Powder)

• Solubility (Oil-soluble / Water-soluble / Dual-soluble)

• pH of Finished Product

• Shelf-life requirement

• Desired Market Category (Natural, Commercial, Premium)

Key Preservation Terms You Should Know

Term	Meaning
Broad-Spectrum	Protects against bacteria, mold & yeast
Anti-Fungal	Targets yeast & mold (Powder masks, gels)
Anti-Bacterial	Protects from bacteria (Cleansers, scrubs)
Antioxidant	Prevents oils from going rancid (Vitamin E, BHT)
Preservative Booster	Enhances preservative effectiveness
Natural-Friendly	Accepted in herbal/eco skincare (EcoCert options)
Self-preserving	Very low water activity (whipped butters, salt scrubs)

 Oil-only products need antioxidants, not preservatives.Water or water-phase products ALWAYS need preservatives.

Cosmetic Preservatives — Master Comparison Table

Preservative	Solubility	Spectrum	Effective pH	Shelf-Life Support	Best For
Liquid Germall Plus	Water-soluble	Broad	≤ 7.5	24–30 months	Creams, lotions, gels, serums
Phenoxy Ethanol	Oil-dispersible / dual	Broad	3–8	24 months	Baby care, serums, creams
Euxyl PE9010	Mainly oil Soluble/ Dual	Broad	3–10	24–30 months	Active-rich & sensitive skin formulas
Phenonip	Oil-soluble	Broad	4–8	30+ months	Balms, scrubs, butters
Optiphen	Oil-soluble	Broad	4–6	18–24 months	Butters, oils, anhydrous blends
Iscaguard PEG	Water-soluble	Broad	3.5–8	18–24 months	Washes, shampoos, lotions
Euxyl K712	Water-soluble	Partial	≤ 5.5	12–18 months	Natural/herbal, hydrosol products
Sodium Benzoate	Water-soluble	Anti-bacterial	≤ 5.5	6–12 months	Powders, herbal masks, gels
Potassium Sorbate	Water-soluble	Anti-fungal	≤ 6.0	6–12 months	Herbal packs, gels, toners
Sodium Metabisulphite	Water-soluble	Antioxidant	4–6	Supports stability	Vitamin C, fruit extracts
BHT	Oil-soluble	Antioxidant	No pH limit	Adds 6–18 months	Oils, balms, hair serums

Which Preservative to Use — Based on Product Type

Product Type	Best Options
Creams & lotions	Germall Plus, Phenoxyethanol, Euxyl PE9010
Gels, hydrosols, rose water, toners	Euxyl K712, Iscaguard PEG, Sodium Benzoate + Potassium Sorbate
Body oils, lip oils, balms	BHT, Vitamin E, Optiphen (if needed)
Powders / Ubtan / Dry masks	Sodium Benzoate + Potassium Sorbate + BHT
Butters & anhydrous balms	Optiphen, Phenonip
Baby / sensitive skincare	Euxyl PE9010, Phenoxyethanol
Vitamin C, herbal extracts	Sodium Metabisulphite + Phenoxyethanol

Oil vs Water Soluble Preservatives — Comparison

Feature	Oil-Soluble	Water-Soluble
Works in	Balms, oils, body butters	Creams, gels, lotions, hydrosols
Examples	Optiphen, Phenonip, BHT	Germall Plus, K712, Sodium Benzoate
pH Dependent?	Less	Highly
Natural-friendly?	Limited	Yes (K712, Sodium Benzoate)
Needed in oils?	Only antioxidants	Yes — if water content exists

How to Decide — Quick Selection Checklist

• Is there water? (Hydrosol, aloe, juice, aqua, glycerine) → Must add preservative

• Is it oil-only? (Serum, balm, butters) → Use antioxidant only

• Is the pH below 5.5? → Use Sodium Benzoate + Potassium Sorbate, Euxyl K712

• Is the formula rich in actives? → Use Phenoxyethanol, Euxyl PE9010

• Want “natural” or herbal branding? → Use Euxyl K712, Sodium Benzoate + Sorbate

Essential Precautions

• Always add preservatives in the cooling phase (below 40–45°C)

• Test final pH after adding actives & preservative

• Never assume natural formulations are self-preserving

• Don’t exceed the recommended % (can cause irritation)

• Perform stability, microbial & challenge testing before selling

Final Formulation Tips

• Use antioxidants in oil-only formulas (BHT, Vitamin E)

• Herbal extracts increase microbial risk — preserve properly

• Products stored in bathroom climates need stronger protection

• Face packs & dry powders need dry preservatives or preservative added at activation time

Disclaimer

For educational and formulation guidance. Always conduct patch testing, microbial testing, pH analysis, and stability testing before commercial production.