UV Filters Sunscreens

UV filters enter the aquatic environment directly as a result of recreational activities when they are washed off from the skin, or indirectly through wastewater resulting from the use of personal care products, washing clothes, and industrial discharges. Residues of more polar organic UV filters have been found in all kinds 

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In this chapter, among the large variety of compounds, we include some of the emerging contaminants most commonly found in sewage sludge pharmaceutical compounds, estrogens, illicit drugs, UV filters (sunscreens), BFRs, and PFCs. 

Uses UV absorber, UV filter, sunscreening agent, skin conditioner in cosmetics Manuf/Distrib. Costec http //www.costec.com] EM Ind. http //www.emindustries.com] Penta Mfg. http //www.pentamfg.com], Quest Int l. 

Sometimes for some very potent pollutants analytical methodologies provide limits of detection (LODs) higher than the concentrations that cause effects, as derived from ecotoxicological studies. Therefore efforts in the field of analytical chemistry (see Sect. 2) are focused on making available the necessary analytical capabilities to detect pollutants at the required low levels found in the environment. This was the case of pharmaceuticals, illicit drugs, perfluorinated compounds (PFCs), sunscreens/UV filters, etc. few years ago. However, this list is likely to increase with new family candidates. 

The concentration levels observed in sewage sludge show that UV filters originate mainly from private households, but besides this, surface runoff and industrial discharges may be considered as additional sources. This indicates that in addition to sunscreens, cosmetics and other personal products, UV filters from plastics, textiles, and other materials can be released to the environment by either volatilization or leaching. 

Poiger, T. Buser, H.-R. Balmer, M.E. Bergqvist, P.-A. Muller, M.D. 2004, Occurrence of UV filter compounds from sunscreens in surface waters Regional mass balance in two Swiss lakes. Chemosphere 55 951—963. 

Two UV filters (used to block UV-rays in sunscreens and other products), octyl-p-methoxycinnamate and octyl-dimethyl-p-aminobenzoate, reacted with chlorine, producing chlorine-substituted compounds as intermediates that finally cleaved to smaller ester products [121]. Some of the identified octyl-p-methoxycinnamate DBPs showed weak mutagenic properties. Chlorinated and brominated intermediates were formed during chlorination of 2-ethylhexyl-4-(dimethylamine)benzoate and 2-hydroxy-4-methoxybenzophenone, with trichloromethoxyphenol the most abundant DBP [122]. 

HPLC METHODS FOR THE DETERMINATION OF ALKYLPHENOL-ETHOXYLATE SURFACTANTS, SUNSCREEN, AND UV FILTERS... 

After developing a method to quantitate the generation of ROS in skin, we could begin to study how the number of ROS can be reduced by the application of FDA-approved UV filters used in sunscreens (Hanson et al. 2006). Our measurements showed that octocrylene (OC), octylmethoxycinnamate (OMC), and benzophenone-3... 

Giokal, D.L., Salvador, A., Cisvent, A. UV filters from sunscreens to human body and the environment. Trends Anal. Chem. 26(5), 360-374 (2007)... 

Finally, yet importantly, cosmetic sunscreen substances can be looked at as materials being exposed to solar radiation. Their photostability can then be evaluated as change of protective potential based on a transmission measurement or loss (or survival rate) of individual UV filters upon exposure to simulated solar radiation. It is in this sense that the term "photostability" is normally used in the context of cosmetic sunscreens. It is also in this sense that the "Photostability of Cosmetic Sunscreens" will be discussed in this chapter (and not in the meaning of drug/lCH guidelines). 

The first photostability measurements performed on cosmetic UV filters were carried out, probably in the 1930s, by Kunz (9). He prepared dilute solutions of UV filters in (cosmetic) solvents, exposed them to artificial UV radiation and recorded the changes in their UV absorption profile before and after exposure. At that time, the term, "sun-protection factor," was unknown and there was no standard methodology to evaluate the protective potential of a sunscreen on human skin. Hence, the behavior of the filter was used as a surrogate for a protection assessment. 

The photostability of sunscreens has been, since the 1990s, primarily a UV-A issue due to the fact that no agreed method was (and still isn t at this time) available to assess the protective capacity of a sunscreen preparation towards UV-A radiation. As in the early days, the photostability of the UV filter or the sunscreen preparation itself was tentatively used instead of a skin-related end point. 

The term "photostability" in the context of UV filters and sunscreen preparations is most often used in either of two ways ... 

Consequently, this kind of analysis may often lead to the premature disqualification of UV filters or UV filter combinations that are often found in sunscreen preparations. 

Optimally, the "analytical" and the "spectral" approaches should be combined. The two are complementary and together provide the most insight into the behavior of a UV filter or a sunscreen preparation. 

When studying UV filters or sunscreen preparations, it is useful and desirable to have some knowledge about the photochemical behavior of the components under study. It is the absence of this knowledge which, over the last two decades, has led to many misinterpretations and erroneous conclusions. 

In 1981, Beck, Deflandre, Arnaud, and Lemaire (16) stated that E A Z, cis A trans isomerization is a desirable process for a UV filter, i.e., "Isomerization E A Z is thus a choice process for a sunscreen agent. In practice, it is this mixture of E and Z forms, which acts as a UV filter and it is therefore the mixture s stability which should be considered rather than that of the initial compound."... 

Schneider P, Bringhen A, Gonzenbach HU. Single step HPLC analysis of sunscreen products containing complex UV-filter systems. Drug Cosmet Ind 1996 32-38, 77. 

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