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Why Cosmetics and Packaging Materials Need Stability Test

July 22,2023

With the development of society and economy, people's pursuit of a better life continues to improve, and cosmetics have become an indispensable consumer product for people. When people choose cosmetics, in addition to paying attention to safety, they also put forward higher requirements for their efficacy.


Cosmetics are compound mixtures made by rationally blending and processing various raw materials.

Cosmetics have a wide variety of raw materials and different properties. According to the raw material properties and uses of cosmetics, it can be roughly divided into two categories: matrix raw materials and auxiliary raw materials. The former is a class of main raw materials of cosmetics, accounting for a large proportion in cosmetic formulas, and is a substance that plays a major functional role in cosmetics. The latter is responsible for the forming, stabilizing or imparting color, fragrance and other properties of cosmetics, which are not used in large amounts in cosmetic formulations, but are extremely important.

Cosmetics are chemical mixtures made of natural, synthetic or extracted substances with different effects as raw materials and processed by heating, stirring and emulsification and other production processes. Cosmetics need to be tested in an environmental environment before being put into production to ensure their stability in their use and storage state.

Stability Test for Cosmetics

Due to the relatively short development cycles of cosmetic products, real-time stability testing is not always practical. Due to the variety of cosmetic products and their inherent complexity, regulatory agencies have not prescribed standard stability testing guidelines. Therefore, cosmetic companies need to design and follow their own accelerated stability testing procedures in order to meet the required testing economically and efficiently. Cosmetic stability studies often include different accelerated storage conditions, where samples are kept at high temperatures (37C, 40C or 45C) for a period of 1 to 3 months, depending on the type of product and the needs of the product. These accelerated test conditions are recognized internationally as adequate for predicting product shelf life in many industries. Protocols designed for cosmetic stability studies include testing of product attributes that are prone to change during storage and which may affect cosmetic quality, safety, and performance characteristics.

As a general guideline, stability testing should be performed in the following situation:

1.For new product development, you only need to choose the best formula, that is, to meet all the important physical, chemical and performance characteristics you need in the product;

2.To reform the market for existing products, any change in the formulation, such as a change in one or more ingredients, a change in the percentage of raw materials, or the use of ingredients from different suppliers, will require new stability tests to anticipate possible unacceptable changes in the product

3.Moving to new packaging, whenever the type or type of container is modified, the compatibility between the formulation and the new packaging should be checked;

4.Modifications in the manufacturing industry, whether it is a change in procedures, replacement of equipment or a new production facility, stability testing should still be done as it may affect product quality;

High Temperature and Low Temperature Storage Stability Test

In order to keep the performance of the product stable during storage and use, without physical and chemical changes, oil leakage, water separation, coarse grains, and demulsification, etc., high temperature and low temperature storage stability tests should be carried out during formulation design. This is the first consideration when designing cosmetic formulations. The environmental conditions of the test should simulate the actual environmental conditions of the product as much as possible, and even be stricter than this possible actual environment. For example, when developing new skin care products for severe cold regions, in addition to conducting low-temperature cold resistance tests at -15°C/24 hours in accordance with the relevant national standards, more stringent cold resistance tests must be carried out according to the actual conditions in the areas where the products are used, and the stability of raw materials and the rationality of the formula must be determined based on the test results.

Observation items include changes in appearance (difference in color tone, fading, uneven color stripes, foreign matter mixed in, scars, floaters, separation, sedimentation, sweating, white powder, floating, pitting, looseness, cracking, gelling, transparency, agglomeration, luster, collapse, cracks, pores, air bubbles, fungal growth, etc.). Odor change (directly, the smell of the container is mixed, when used). The high temperature and low temperature storage stability test in the laboratory can be carried out by the following methods:

Testing Conditions Time
Room temperature 25°C 3 years product shelf life test
Accelerated test Generally 40°C or 37°C, 50°C, 3-6 months
Low temperature test 5°C 3-6 months
Temperature cycle test Three cycles of -10°C to 40°C; 48-hour a cycle
Light test Xenon Arc Weathering Test

① Place it in a 40°C-50°C electric constant temperature incubator for 30-50 days, and observe after returning to room temperature

② Within 24 hours, frequently change back and forth between 0°C-50°C, repeat the operation for 15-30 days, and observe after returning to room temperature

③ Cycle storage at -5°C and 40°C for 3 times, each time for 24 hours, that is, store at -5°C for 24 hours, store at room temperature for 24 hours, and then store in a 40°C incubator for 24 hours, cycle 3 times in order to observe its stability

④ Store at -5°C for 1 week to observe its stability

Temperature and Humidity Test Chamber provide a high-precision test environment for durability testing of cosmetics, chemical, pharmaceutical and electronic products

LIB has a wide selection of standard and custom Hot And Cold Chamber. They are available to suit many types of environmental test conditions. Our test chambers are available in a variety of sizes and configurations, from 50 litre to 3000 litre, including bench, floor and walk-in. It can perfectly perform a series of environmental tests such as high temperature test, cold test and constant temperature test, thermal shock test. Our LIB stability chambers have basic performance and good reliability for long-term continuous operation. The test chamber also has the advantages of easy operation and easy maintenance.


Xenon Arc Weathering Test for Cosmetics Packaging Materials

The main purpose of xenon arc aging test for cosmetic bags is to evaluate the durability and stability of cosmetic bags after long-term use. Cosmetic bags usually use plastic materials, which are easily affected by factors such as oxidation, ultraviolet rays, and heat, resulting in color changes, aging appearance, and reduced functionality. The xenon arc aging test can simulate these factors and accelerate the aging process of the test samples, so as to evaluate the performance and life of the cosmetic bag more quickly and accurately.

● working principle

The main working principle of the xenon lamp aging test for cosmetic bags is to use the high-intensity radiation and ultraviolet radiation of the xenon lamp to simulate the light and oxidation factors in the daily use environment. The test samples are placed in the aging test equipment, and the actual use conditions are simulated by xenon lamp radiation and ultraviolet radiation, such as sunlight exposure and air oxidation in indoor and outdoor environments. By controlling parameters such as temperature, humidity and ultraviolet radiation intensity in the test equipment, the aging process under different usage environments can be simulated.

● operation method

Design test plan: According to the characteristics and requirements of cosmetic bag materials, design a test plan that meets the actual needs, including the determination of test time, temperature, humidity and ultraviolet radiation and other parameters.

Install the test equipment: choose the appropriate xenon arc and ultraviolet radiation test chamber (LIB UV and Xenon Arc Accelerated Weathering Test Chamber), and set the parameters and working mode.

Prepare cosmetic bag samples: According to the designed test plan, prepare the cosmetic bag samples to be tested, and place the sample holder in the test equipment.

Test: Expose the cosmetic bag samples in the test equipment to xenon lamp irradiation and ultraviolet irradiation, control the test time, temperature, humidity and ultraviolet irradiation parameters according to the designed test plan, and record the test data.

Analyze test results: Analyze the aging of cosmetic bags based on test data, including color changes, appearance aging, and functional degradation.

Report writing: According to the test results, write a test report, including test purpose, test method, test result and conclusion, etc., to facilitate subsequent data analysis and technical improvement. At the same time, maintain and maintain the test equipment to ensure its long-term stable operation.


The xenon lamp tube in LIB Xenon Arc test chamber can simulate the solar spectrum, so that the cosmetic bag is exposed to the light environment similar to the sun in the test. At the same time, the ultraviolet irradiation device can simulate ultraviolet radiation in sunlight to test the ultraviolet protection performance of materials. By testing the cosmetic bag samples under different conditions of time, temperature, humidity and ultraviolet radiation, the actual use environment can be simulated, the performance and stability of the material after long-term use can be evaluated, and a scientific basis can be provided for the quality and performance of the product.

Cosmetic bag xenon lamp aging test is to evaluate the light aging resistance of cosmetic bag materials to determine the anti-aging ability of the bag under long-term sunlight exposure, as well as the stability and durability of the material after long-term use. The test results can be used to improve and optimize the formulation and manufacturing process of bag materials to improve product quality and performance, and can also be used to ensure the safety and reliability of cosmetic bags and ensure the health and interests of consumers. The operation method of xenon lamp aging test for cosmetic bags needs to strictly follow the test plan, and accurately control and record the test parameters. At the same time, the maintenance and maintenance of the test equipment is also very important to ensure the accuracy and stability of the test equipment and avoid test errors and unreliable test results. The writing of the test report needs to clearly and accurately describe the test process and test results, so as to facilitate subsequent data analysis and technical improvement.


Cosmetics have a long history of use and are widely used in daily life by the majority of beauty lovers. It is very important to understand the raw materials and stability related tests of cosmetics. LIB has more than 10 years of experience in this field, come and choose the environmental test chamber suitable for cosmetic testing.


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