slow‑evaporating, “non‑tacky” solvent is needed: hair sprays, colourants, styling mousses/gels; facial toners, serums and essences; make‑up primers, foundations and powder

PPG‑3 Methyl Ether (Tripropylene Glycol Methyl Ether, TPM)

EWG’s product database and public ingredient lists show TPM appearing in a broad spread of categories—especially where a slow‑evaporating, “non‑tacky” solvent is needed: hair sprays, colourants, styling mousses/gels; facial toners, serums and essences; make‑up primers, foundations and powders; deodorants, cleansing wipes and nail‑polish removers.

Key facts

Why formulators pick it

Safety & regulatory status

• EU: Listed in CosIng only as a “Solvent”; not restricted in Annex II/III, so it may be used without a specific concentration cap provided finished‑product safety is demonstrated.
• US/Canada/Japan: No specific prohibition; CIR Expert Panel concluded TPM (PPG‑3 Methyl Ether) is “safe as used” in cosmetics at the concentrations reported (0.4–2 %).
• Toxicology highlights: Low acute toxicity, minimal skin/eye irritation, not sensitising or genotoxic; rapid renal clearance if absorbed. Aerosol particle sizes in hair sprays are typically non‑respirable.
  
  

Formulation tips & compatibility checklist

1. Target pH 3–10: TPM is stable and shows no hydrolysis across normal cosmetic pH ranges.
2. Water first: Add TPM after water‑soluble humectants; it will self‑couple oils.
3. Plastic compatibility: Avoid Buna‑N, neoprene, and certain butyl rubbers in gaskets—these swell in prolonged TPM contact; stainless‑steel or PTFE parts are preferred in process equipment.
4. Flash‑point buffer: With its 93 °C flash point, TPM usually keeps even alcohol‑containing sprays in the “combustible” (not “flammable”) class, easing shipping.
5. Aerosols: Because of slow evaporation, pair TPM with a faster co‑solvent (e.g., ethanol 10–25 %) to optimise drying time in hair sprays or setting sprays.
6. Preservatives: Fully miscible with phenoxyethanol, ethylhexylglycerin and most parabens; no known negative synergy.
   
   

Quick formulation reference

Take‑aways

• TPM is essentially the “slow, soft, water‑friendly” member of the propylene‑glycol‑ether family—perfect when you need strong solvency without the sharp odour or quick flash of lower‑glycol ethers.
• It is broadly permitted and judged safe at up‑to‑low‑single‑digit percentages in leave‑on and rinse‑off products.
• Treat it as a multi‑purpose helper: solvent, coupling aid, humectant‑feel adjuster and (at higher levels) penetration booster—so long as your packaging elastomers and VOC targets are compatible.

Usage: Mix in serum, lotion or cream.

Mixing method: Can be mixed in several steps.

Usage rate: 1-20% (do not use more than 50%)

Product characteristics: Clear liquid, similar to oil.

Solubility: Soluble in water.

Storage: Can be stored at room temperature, but close the bottle tightly and keep away from sunlight or heat. The product has a shelf life of at least 2 years.

INCI Name : PPG‑3 Methyl Ether