Stability

Shelf-Life Predictor

Convert accelerated oven-aging results into real-world shelf life using the Q10 rule or the Arrhenius equation. Survives the test ≠ stable forever — these are best-case estimates.

Stress temperature (°C)Target storage temperature (°C)Days survived at stress tempQ10 factor (2 lipids, 3 emulsions, 4 actives)

Q10 assumes the degradation rate multiplies by Q10 for every 10 °C drop. Conservative for cosmetics: use 2.

Predicted shelf life at 25 °C

Acceleration factor

6.25×

Days

563

Months

18.5

Years

1.54

Good — typical cosmetic shelf life

Protocol guidance

Standard cosmetic protocol: 12 weeks at 45 °C + 4 °C + 25 °C (cycle 50 °C / -10 °C optional).
3 months at 45 °C ≈ 24+ months at 25 °C (Q10 = 2.5). Many brands publish PAO 12M from this.
Do not extrapolate emulsions above 50 °C — separation mechanics change and Arrhenius breaks down.
Vit C / retinoids: use Q10 = 3–4; degradation accelerates nonlinearly.
Microbial challenge (PET) is separate from oven aging — see /preservation.

References: Arrhenius (1889); cosmetic application in Schueller & Romanowski, "Conditioning Agents for Hair and Skin" (2nd ed.). Always confirm with real-time stability before committing to a long PAO.