If you make or sell cosmetics, you have probably heard that you need to get your products "stability tested" before they go to market. But what does that actually mean, and why does it matter so much? This guide breaks it down in plain language.
Cosmetic stability testing is the process of checking how a product's physical, chemical and microbiological properties hold up over its intended shelf life. In short: will the product still be safe, effective and pleasant to use months or years after it was made?
Why stability testing matters
A cosmetic is a chemistry experiment that has to stay stable on a shelf, in a bathroom, in a hot car and in your customer's hands. Over time, ingredients can separate, oxidise, change colour or smell, lose viscosity, drift in pH, or stop being protected against microbes.
When that happens before the product's stated expiry, it can become unsafe or simply unusable — leading to complaints, returns, retailer delisting, or in the worst case a recall. Stability testing is how you catch these problems before your customers do.
What gets measured
Stability testing tracks the things that reveal trouble early: appearance, colour and odour; phase separation; pH; viscosity; and preservative efficacy (the product's ability to fight off bacteria, yeast and mould). These are measured at intervals so you can see how the product changes over time.
Because most problems develop slowly, the measurements are taken under conditions designed to speed up ageing — which brings us to accelerated testing.
How accelerated testing works
Waiting three years to confirm a three-year shelf life is not practical for most businesses. Accelerated stability testing solves this by storing the product at elevated temperatures, which speeds up the reactions that cause degradation.
We test over three months at 40°C, 45°C and 50°C, with each temperature mapping to a 1, 2 and 3-year equivalent shelf life. See our accelerated stability testing service for full details on what is included and how to get started.
What you get at the end
The output of stability testing is a written report documenting the method, conditions, results at each interval, and a conclusion about the shelf life your product supports. A good report is ACCC-compliant and ready to share with retailers, insurers and regulators.
In Australia, this documentation is an important part of demonstrating that your cosmetic is safe for its intended use over its whole life on the market.
Frequently Asked Questions
Do all cosmetics need stability testing?
Any cosmetic you intend to sell should have a documented, evidence-based shelf life. Stability testing is the accepted way to establish that and demonstrate the product stays safe over time.
How much does stability testing cost in Australia?
Pricing depends on how many products you submit and whether you add preservative efficacy (PET) testing. Stability testing starts at $1,400 AUD for your first product, and you can get an exact price in minutes with our instant quote tool.