Avobenzone

(in 1,877 products)

1. Sunscreen - Physical sunscreens work by deflecting or scattering UV rays. Chemical sunscreens work by absorbing and dissipating the UV rays as heat.

Avobenzone is a sunscreen blocker. Avobenzone is a topical, broad range UV protector and blocks UVA I, UVA II, and UVB wavelengths, thereby limiting the impact of UV rays on skin. [1]

Avobenzone is predominantly used as a chemical sunscreen ingredient.

Chemical sunscreens typically work by absorbing the UV rays from the sun and then dissipating it as heat.

In a comparison between avobenzone and other sunscreen ingredients such as octinoxate, octocrylene and oxybenzone, after a 1% topical application, no traces of avobenzone can be detected at the receptor level after 24h. [2] However, avobenzone has the potential to affect human trophoblast cells (outer cells of the blastocyst, where a blastocyst is a ball of cells formed during early stages of mammalian development). It suppresses proliferative activity (prevents cells from replicating) and induces apoptosis (causes cell death) of human trophoblasts. [3] In vitro studies have also shown that avobenzone does possess "anti-androgen-, (anti)-glucocorticoid-, and (anti)thyroid hormone-like activities", but the results weren't significant. It was stressed that more in vivo studies are needed and that the combination of various other sunscreen ingredients has the potential of endocrine disruption. [4]

It also appears that the addition of avobenzone can cause the photolysis (decomposition of an ingredient by light) of other sunscreen agents like octinoxate. [5] Whereas octocrylene photostabalizes it. [6] "Avobenzone has been reported to be unstable when contained in formulations with physical sunscreens." and therefore in the USA, combinations of avobenzone and physical sunscreens are not permitted. [7]

In the environment, avobenzone can be transformed into a multitude of products under aquatic chlorination and UV radiation. It is unknown whether these compounds may cause allergic skin reactions and other possible irritations. [8]

Although avobenzone appears to have the quickest elimination from the human body, it has the potential to affect human trophoblast cells during early stages of pregnancy. There is evidence of avobenzone being an endocrine-disruptor though the results weren't significant. The properties of avobenzone is easily affected by other sunscreen ingredients and it can also breakdown via chlorination or UV radiation to form many other compounds where their effects on humans are unknown.

1. PubChem: https://pubchem.ncbi.nlm.nih.gov/compound/51040

2. Sunscreen Penetration of Human Skin and Related Keratinocyte Toxicity after Topical Application (Skin Pharmacol. Physiol. 2005;18:170–174 DOI:10.1159/000085861)

3. Avobenzone suppresses proliferative activity of human trophoblast cells and induces apoptosis mediated by mitochondrial disruption. (Reproductive Toxicol., 81, 50–57. DOI:10.1016/j.reprotox.2018.07.003)

4. Endocrine activity of AVB, 2MR, BHA and their mixtures. (Toxicol. Sci., kfw253. DOI:10.1093/toxsci/kfw253)

5. Unexpected Photolysis of the Sunscreen Octinoxate in the Presence of the Sunscreen Avobenzone. (Photochem. Photobiol, 81(2), 452–456. DOI:10.1111/j.1751-1097.2005.tb00207.x)

6. Human Safety and Efficacy of Ultraviolet Filters and Sunscreen Products. (Clin. Dermatol., 24(1), 35–51. DOI:10.1016/j.det.2005.09.006)

7. Potential of herbs in skin protection from ultraviolet radiation (Pharmacogn Rev. 2011 Jul-Dec; 5(10): 164–173. DOI:10.4103/0973-7847.91114)

8. Transformation of avobenzone in conditions of aquatic chlorination and UV-irradiation (Water Res., 101, 95–102. DOI:10.1016/j.watres.2016.05.067)

1. EU CosIng Annex VI, LIST OF UV FILTERS ALLOWED IN COSMETIC PRODUCTS [2017]

- Ref: VI/8