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Method for determination of sun protection index of cosmetics
The purpose of the research is to establish a method for determining the sun protection index of cosmetics consistent with ISO by measuring the sun protection index of sunscreen ingredients and comparing the consistency of in vivo and in vitro testing methods. Research content 1. Sun protection index (SPF value) test of 12 sunscreen cosmetic ingredients; 2. Longwave ultraviolet protection index (PFA value) determination of 6 sunscreen cosmetic ingredients; 3. Applicability of testing according to ISO sun protection function test method. Test substance 1. Sunscreen agents are 14 kinds of sunscreen agents that are restricted by the 'Hygiene Regulations for Cosmetics (2007 Edition)Among them, 12 measures SPF value, 6 measures PA value, the relevant information is shown in Table 1. 2. Reference substance PA: S1 is 4.0 (ISO24442 reference value is 4.4±0.6); SPF: P7 is 4.0 (ISO24444 reference value is 4.4± 0.4). Subjects All subjects are required to sign a written informed consent form after being informed of the relevant contents of the experiment. All tests should comply with the basic principles of the International Declaration of Helsinki and national regulations on human tests. 1. Selection criteria 1.1 Choose healthy volunteers aged 18 to 60, both male and female 1.2 SPF test Subject requirements: skin type is type II or type III, that is sensitive to sunlight or ultraviolet radiation, easy to appear after exposure Those who are not prone to hyperpigmentation due to sunburn; and the subject's skin colorimetric ITA° value should be> 28° 1.3 Requirements for the subjects of the PA determination: the light skin type is type III or type IV, that is, people with different degrees of pigmentation after ultraviolet radiation; and the tester's skin colorimetric ITA° value is 20° to 41 °between. Exclusion criteria 2.1 A history of photosensitivity diseases or recent use of drugs or foods that affect skin photosensitivity 2.2 Use of immunosuppressive agents in the past month 2.3 Recent oral or topical use of anti-inflammatory drugs such as corticosteroids 2.4 Skin of the test site Pigmentation, inflammation, scars, pigmented moles, hirsutism, etc. 2.5 Breastfeeding or pregnant women 2.6 Immunodeficiency or autoimmune disease patients, such as HIV-positive patients or patients who have undergone organ transplantation 2.7 Receiving antibiotics within the past 6 months Cancer chemotherapy or radiotherapy 2.8 Those who cannot avoid frequent sun exposure on the test site 2.9 Those who are highly sensitive 2.10 Those who have undergone a similar test in the past two months 2.11 Those who have participated involuntarily or cannot complete the specified content as required by the test 3. Accepted The number of test subjects The number of test subjects in each test should be no less than 10, and the maximum number is 25. Test method 1. Sun protection index (SPF value) test method of sunscreen cosmetics 1.1 Selection of standard reference substance As expected SPF value <20, any of the following standard reference substances can be used: P2, P3 or P7. If the SPF value is expected to be ≥20, one of the following standard reference substances can be used: P2 or P3. If a standard reference substance with a high SPF value is used, even if a test sample with a low SPF value is tested in the experiment, there is no need to use a standard reference substance with a low SPF value for control. 1.2 The artificial light source used in the light source must be a xenon arc lamp daylight simulator and equipped with a filtering system. The ultraviolet daylight simulator should emit a continuous spectrum, which has no gaps or extreme emission peaks in the ultraviolet region. The light source output of the ultraviolet daylight simulator should be stable and uniform across the entire beam section, and an appropriate filtering system must be equipped to make the output spectral characteristics meet acceptable limits. The spectral characteristics are described by the cumulative erythema effect in the continuous band of 290nm～400nm. The erythema effect of each band can be expressed as the percentage value of the total erythema effect of 290nm～400nm, that is, the relative cumulative erythema effect. The %RCEE requirements of the light source output are shown in the following table. 1.3 Determination of the minimum erythema (MED) 1.3.1 The UV exposure time and the subject’s posture should be within 15 minutes and 30 minutes after applying the test sample Begin to irradiate the test site with increasing doses of ultraviolet radiation. During the entire irradiation period, the subject's posture should remain the same as the posture when applying the sample. 1.3.2 Determination of the minimum erythema (MEDu) at the unprotected test site Before the actual test, a temporary MEDu needs to be measured to determine the intermediate range of UV doses irradiated by MEDu and MEDp. The measurement of provisional MEDu is a pre-test, which first determines the subject's MEDu before setting the experimental MEDu. For each subject, the MEDu for unprotected skin should be measured on the same day as the MEDp for skin protected by the test sample. 1.3.3 Determine the minimum amount of erythema (MEDp) at the test site using the product to protect the test site. Choose an irradiation area on the back skin of the subject. In the case of using sunscreen cosmetics for protection, take different doses of ultraviolet radiation. The maximum increase in irradiation time does not exceed 25%. 1.3.4 Increasing base of UV dose For test sites that are not protected by sunscreen cosmetics, the subject's temporary MEDu, estimated MEDu or expected MEDu can be used to determine the UV dose range. Use increasing doses of UV light to irradiate at least five secondary sites centered or adjacent to the provisional/estimated MEDu in accordance with the recommended order of 1.25 times.
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The Heat Contact Machine GT-C101 is a specialized testing instrument designed for evaluating the heat resistance and thermal protective performance of gloves, protective clothing, and other heat-resistant materials used in high-temperature environments. In industries such as smelting, casting, welding, and glass manufacturing, workers are frequently exposed to intense heat, making accurate testing of contact heat resistance essential for ensuring safety and compliance.
GT-C101 simulates real working conditions by measuring heat transfer delay and thermal transmission under instant contact with high-temperature surfaces. Fully compliant with EN 407, EN 702, and ISO 12127-1 standards, this machine provides precise, repeatable data for manufacturers, laboratories, and research institutions. With high-temperature capability up to 500°C, advanced calorimetry, digital monitoring, and adjustable contact speed, the Heat Contact Machine GT-C101 is an indispensable tool for developing and certifying next-generation PPE and heat-insulation materials.
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