• Title/Summary/Keyword: sun protection

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A Test to Compare the Water Resistance Sun Protection Factor of General Water, Artificial Seawater, and Natural Seawater of Sunscreen (자외선 차단제의 일반 물, 인공 해수, 자연 해수의 내수성 차단지수를 비교하기 위한 시험)

  • Hyoung Hoon Hwang;Eun Young Kang;Su Yeong Kim;Hui Jeong Jung;Jun Seong Yang;Won Kyu Hong;Hong Suk Kim
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.49 no.4
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    • pp.349-354
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    • 2023

  • Sunscreen is a product that protects against ultraviolet rays by blocking and scattering ultraviolet rays, and has now become a daily necessity beyond cosmetics. Applying sunscreen is a common and easy way to prevent skin damage caused by ultraviolet rays. Due to its significance, the evaluation of sunscreen has evolved since its regulation by the FDA in 1978, progressing to standardized methods established by ISO. Additionally, to assess the loss of sunscreen due to activities such as water exposure or sweating, the Ministry of Food and Drug Safety in Korea and ISO have established protocols for evaluating the water-resistant sun protection factor (SPF). However, existing evaluations of water resistance have been mainly confined to test methods involving plain water, and methods accounting for the impact of seawater during activities like beach leisure, sports, and recreation are yet to be established. Based on the existing guidelines for testing the water-resistant UV protection index, this study compared the water-resistant UV protection index in water, artificial seawater (salt water) and natural seawater (sea water) to evaluate the UV protection index in real-world situations such as marine leisure, sports, and leisure activities. Through these results, we were able to compare the differences between water resistance sun protection index tests in ordinary water, artificial seawater, and natural seawater, and suggest a method for water resistance sun protection index tests using natural seawater.

  • https://doi.org/10.15230/SCSK.2023.49.4.349 인용 PDF

Characteristics of Double Polarity Source-Grounded Gate-Extended Drain NMOS Device for Electro-Static Discharge Protection of High Voltage Operating Microchip (마이크로 칩의 정전기 방지를 위한 DPS-GG-EDNMOS 소자의 특성)

  • Seo, Yong-Jin;Kim, Kil-Ho;Lee, Woo-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.97-98
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    • 2006

  • High current behaviors of the grounded gate extended drain N-type metal-oxide-semiconductor field effects transistor (GG_EDNMOS) electro-static discharge (ESD) protection devices are analyzed. Simulation based contour analyses reveal that combination of BJT operation and deep electron channeling induced by high electron injection gives rise to the 2-nd on-state. Thus, the deep electron channel formation needs to be prevented in order to realize stable and robust ESD protection performance. Based on our analyses, general methodology to avoid the double snapback and to realize stable ESD protection is to be discussed.

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Immune Protection Factor of Sunscreens in Humans is Dependent on Protection from UVA and Cannot be Predicted from the Sun Protection Factor

  • Halliday, Gary M.;Poon, Terence S.C.;Damian, Diona L.;Barnetson, Ross St.C.
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.236-239
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    • 2002

  • Sunscreens have been advocated as an important means of preventing skin cancer. UV-induced immunosuppression is important for skin cancer development, yet the effectiveness of sunscreens in protecting the human immune system from UV radiation is unclear. The only currently accepted method of sunscreen rating is the Sun Protection Factor (SPF) based on prevention of erythema. We developed an in vivo non-invasive method for evaluating protection of the human immune system from UV radiation based on recall contact sensitivity to nickel, a common allergen. Using this system we showed that broad-spectrum sunscreens provide greater protection to the immune system than sunscreens which protect from UVB only. UVA was found to be immunosuppressive. We developed this technique to enable the study of solar simulated UV radiation dose responses and determined Immune Protection Factors (IPFs) for six commercially available sunscreens based on limits of protection from the dose response data. We found that the IPF did not correlate with the SPF and that protection from erythema therefore cannot be used to predict protection of the immune system. However, IPF was significantly correlated to the UVA protective capability of the sunscreens, indicating that sunscreen protection from UVA is important for prevention of immunosuppression. We recommend that sunscreens should be rated against their immune protective capability to provide a better indication of their ability to protect against skin cancer.

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