 Hello, I'm Charles Menzie pleased as the chair of the committee to give you an overview of the work that we did with an emphasis on some of the key data gaps and information needs that we're hoping will be addressed during this workshop. The workshop committee was quite diverse. As we were covering a wide range of topics from ecological topics to toxicological topics to human behavior. And implications for sun exposure. We were supported by a great staff with the National Academy. Who really carried us forward. And importantly, this, this study was funded by the US Congress. And sponsored by the US environmental protection agency. The report itself was designed to provide information for future application and ecological risk assessment. On the environmental side. And to that end, the committee reviewed the available information on sources of UV filters in the environment. Their fade processes. The measurements of those chemicals in the water, sediment and biota. And their environmental effects. And we provided our findings and knowledge gaps in each topic area. As well as overarching conclusions and recommendations that I'll I'll speak to today. As a result of the of the work that was done. Was decided that it made a lot of sense to have a follow up workshop that you'll be participating in. And that workshop. We'll focus on the aquatic environmental effects. So a key portion of the. Of the information that was brought to bear to think about ecological risk assessment. On the 1st day. We'll be looking at the analytical challenges working with UV filters. These are critical for achieving accurate toxicity metrics. And on the 2nd day. We'll be looking at toxicity testing with a focus on testing on non standard organisms. Throughout we will discuss and encourage progress on knowledge gaps across the government industry and academia. How many of you are familiar with the idea of. Bringing information together at various levels. So the regard to effects. What this diagram shows is on the far left. Beginning with simpler tests such as Q SARS and extending all the way to the right with model ecosystems. And in seed to bio monitoring. Effects information might be gathered. And the notion is that. At each stage, you learn something more. And you reduce the uncertainty. About understanding the effects. And or the exposures. Often this is approaches put into a tiered system where you do simpler tests 1st, and then you may progress. But this is the committee's thinking in terms of how 1 would. Bring together the appropriate toxicity information for addressing the risk questions at hand. Now the committee looked at 17 UV filters specifically those that are marketed in the US. 15 of these are organic chemicals. And to titanium dioxide and zinc oxide are in organic chemicals. And the study. Looks at each and develops information for each. One of the challenges in working with these chemicals. Is dealing with their chemistry. And being able to analyze them properly in a way that we both understand. What exposure levels are. In test systems. As well as in environment in the environment. So with regard to the hydrophobic. The hydrophobic. Or organic UV filters. There's a variety of. Of processes that can occur once these enter enter into the water. And these include everything from the physical mixing. To absorbing to various organic particles that might be in the water. To becoming deposited in sediments as a result of that adsorption. To transformations either bio degradation type transformations or. Through photolysis catalysis from the sun. There's a range of hydrophobicity. Across these compounds, some being very. Hydrophobic and more likely to want to. Bind to. Organic materials in the water or be taken up by animals and plants. Some are. Very soluble such as solute solacea benzone. Then there are others that are in between such as oxy benzone, which is moderately water soluble. For the inorganic UV filters zinc oxide and titanium dioxide. There are also a variety of things that may happen once they're in water. These 2 can include photo reactions. This solution as in the case of zinc oxide, which readily dissolves. As well as forming agglomerates. And settling to the sediments would be a very common thing for tiny particles of these. Particularly UV filters. With respect to biodegradation and biodegradable biodegradable biodegradability. There are numerous standard tests for biodegradation, but these are designed for wastewater for the most part. And they do indicate that a number of compounds are non biodegradable, including have a benzone. Dioxy benzone octacrylene. There are very few tests that have been done that look at the biodegradation of these compounds in natural water systems. With regard to photo stability. We do know that oxy benzone and solicit benzone appear to be relatively photostable in laboratory settings. Avobenzone, which is commonly used in many some screen products can be photostable, but that's highly dependent on the molecular scale of the environment. And frankly, the photo stability for other UV filters is largely unexplored. The committee looked at the propensity of these chemicals to bio accumulated to into aquatic life. That may come from chemicals in the sediments from the water or via the food path food chain pathways. And on the right. We have the information for the organic. UV filters that kind of shows their co W's, which is a measure of how likely they are to want to be present in fat. Versus water and you can see that there are a number of compounds, a select number of compounds that have higher. What we call KOW's partitioning coefficients. Examples of those are our avobenzone and octacrylene would have high ones while others are low. Such as solicit benzone. And that when we'll therefore dictate to some degree where those chemicals will come to reside with respect to aquatic biota. There have been a number of high quality laboratory based tests. And information available and on the on the right here are seven compounds for which. We have information that provides insight on their bio accumulation, which could be described for the for the group as a whole as ranging from low to moderate. Bio accumulation, there are a number of knowledge gaps. To be considered in understanding the exposure and testing dosages. Most of the understanding of physical chemical parameters comes from laboratory of pure water experiments and modeling platforms. Photo transformation of the UV filters and aquatic environments. That is without the use of solvents is significantly understudied. Limited data exist on the role of some common coatings. Apply to inorganic UV filters on their aggregation or dissolution. Field studies of tissue concentrations lack comprehensive characterizations of UV filter exposure and water and sediment. We do know that these chemicals accumulate in marine and aquatic organisms. But the statement means that we don't understand what the exposure regime was that led to those real those specific body concentrations. And there's a need for standard guidelines on bio concentration under laboratory conditions for saltwater organisms. And improved studies of critical body residues in acute and chronic exposures to understand bio accumulation and toxicity. Critical UV filters are really difficult and challenging to work with. And this impacts both toxicity testing and monitoring the environment. The diagram shows some of the glassware involved and some of the steps involved in either making measurements either in connection with toxicity testing studies or field studies. And there's lots of opposite opportunities here for the chemicals to absorb to containers to be lost from containers. And so this is a this is a key challenge in understanding what are the true dose response relationships and doing toxicity testing as well as what are the true exposures. Accurate exposures in in aquatic and marine environments. Another key knowledge gap here is that robust chemical analytical procedures are needed to better reflect UV filter concentrations over time and space. And that is both at the scale of a test system a toxicity test system and in the environment. This may include minimum replicates and reliable standardized methods developed to collect extract and process samples so that they accurately measure the UV filters. This includes minimum QA QC procedures. For example, analytical and in matrix recovery spikes and the like. I'd like to now turn to information on the ecotoxicology of the UV filters. The committee did a, I would consider a fairly rigorous review of the available studies. We understand that EPA will eventually do its own review, but this helps tee up the studies for consideration for ecological risk assessment purposes. So category one studies were those that were considered useful for ecological risk assessment directly category two were studies that may be useful to ERA or provide additional knowledge. There was a group that was not considered for ERA because of study limitations such as inadequate controls or some other aspects of the study. And then there are studies that include non ERA endpoints. And these are discussed in the report. In a section referred to as studies informing modes of action. Now. You've all have the report and the details on these toxicity studies are assembled in several supporting appendices, which are important to review. Appendix E includes the UV filter toxicity data. Appendix F includes studies on behavioral and physiological endpoints on select organic UV filters. So it'd be good to peruse those and be familiar with them in advance of the meeting. I'd like to touch on laboratory toxicity testing information a bit and I'm using here. The data that we've assembled on acute toxicity. The figure shows the LC 50s on the Y axis and micrograms per liter. And on the X axis are the, are compounds that have been tested, including a number of the organic compounds. And the two inorganic compounds. There is a line, a dash line at 1000 micrograms per liter, 10 of the 3rd that we use as a gauge in making some judgment about whether toxicity values tend to be higher or lower than that value. And we use that value because it helps us orient to the, what we know of the measured concentrations in the environment, which are for the most part. They range from range up to maybe 10 micrograms per liter. Although there are individual values that can for some compounds that can get higher than that. So as you can see from this figure acute toxicity has been observed under that 1000 microgram per liter gauge for several other compounds. The toxicity values typically exceed solubility for the poorly soluble UV filters. If you look at the figure on the right, you see these dash lines here, here, here, here and here. Those are the solubility limits for those compounds. And so if we take this chemical, for example, you'll see that the available data exists above the solubility limit. Here's one where we have something below the solubility limit, but much of the data. Well, for these are existing above the solubility limits. While not shown here, chronic studies are limited across all UV filters. And we'd really like to get at that because of the nature of the exposure. The toxicity information is also given for in a couple of cases for chemicals for which we had sufficient data. So oxybenzone acute data is on the left and oxybenzone chronic is on the right. And you can kind of see where the HC5 is and the LCL values here on the far left for the acute and for chronic. These can also be put together for zinc oxide for acute and chronic and octanoxate and titanium dioxide for acute only. But that is largely the limits of the available data. So other effects that are addressed in the report that you may consider during the course of the workshop include how to think about mixtures. Because of UV filters are typically used as mixtures. There might be several in a particular application. They exist in the environment as mixtures and if you make measurements in the environment, you could find 3, 4, 5 UV filters present detected. So mixture considerations may be important in terms of how they may act together among themselves and with other chemicals. Also important are studies informing modes of action. So there's a section in the report that's devoted to this and we flag the idea of new approach methods and methodologies because, you know, we certainly understand that's a direction that EPA would like to go in in the future. Multiple stressors are key considerations, especially in the marine and aquatic environments where there's a there are other stressors taking place. In particular, those associated with global warming. So water temperature can be an important consideration and how that might interact with the presence or influence the toxicity of chemicals that may be in the water as well. We note in the report. Information on threatened endangered species. A number of the marine. Systems or species and freshwater systems are threatened and endangered. And it may therefore may be of value to think about toxicity testing that would serve to inform the potential for effects on these types of species. And that would be obviously using surrogate species for them. And finally, communities and ecosystems. Systems such as coral reefs are complex. Both in terms of communities and ecosystems and there's a lot going on there and so that affects on one aspect of that system could have effects on other aspects of that system. And the report talks about that. Some of the key knowledge gaps. That will serve to inform higher tier risk assessment, including the creation of those. SSDs when deemed necessary include toxicity tests for non standard organisms, especially marine organisms. Toxic toxicity tests on benthic organisms that may be exposed to UV filters present in the sediments. Effects from UV filter, degradation, there is a level of biodegradation and fatalities that occurs in these environments. Studies that distinguish among inorganic, particulate properties other than particle size. Research on community and ecosystem dynamics. And finally, studies that link downstream cellular tissue, Oregon individual and population responses to population endpoints. Here, we're obviously referring to the development and use of adverse outcome pathways. We were found that we were unable to complete such a pathway, given the available information. The conclusions of the report include this matrix, which I'll just touch on. And just because you might find it useful in thinking about the chemicals as you come to the workshop. So this is arranged with the chemicals across the top and alphabetical alphabetical order, although the organics and then the inorganics. And it's organized into categories. So this first one appears UV filter production and then that's followed by environmental fate and exposure. And the idea is that this is these provides synopsis of information we know about the compounds. And they're color coded. So where something has maybe has a lower influence on environmental conditions, either in terms of exposure and effects, it may get a blue color. If it has a higher potential influence, it might get a brown color like this orange color. If it's in the middle, it might be a yellow color. So when you look at this collectively, it's handy. It's a handy way to kind of see where the blues and oranges and yellows cluster and what information is available about these chemicals. And this really serves to identify where some of the key data gaps are on a per chemical basis. The committee made two recommendations, which bear on the work of this workshop. The first is that EPA should conduct conduct an ecological risk assessment for all currently marketed UV filters in any new ones that become available. This was seen as an urgent need driven by the evidence of local exposures of aquatic organisms in UV aquatic ecosystems to the UV filters. Potentially including endangered species and experimentally demonstrated potential for environmental impact either alone or in context of other system. Stressors and you may recall that one figure I showed you with the dashed line at 1000 and where the measurements and estimates of UV filters were in the environment. Those are within an order of magnitude or two. And given the uncertainties in the information. It's it's easy to see how those could come to converge or overlap, which is why we think it's urgent to look at this. The results of that era that eventually gets. Conducted by the agency would then we would recommend be shared with FDA for their considerations. Of the environment in their oversight of UV filters. Our 2nd recommendation. Is that EPA and partner agencies such as Noah and others. And the sunscreen formulators and the UV filter manufacturers should conduct fund or support and share research. And data on sources, fake processes, environmental concentrations. Biocumulation studies modes of action and ecological and toxicity testing for UV filters alone. And as part of sunscreen formulations. And on the human health side of this we additionally recommend that epidemiological risk modeling behavioral studies. Related to sunscreen usage should be conducted to better understand human health outcomes. From changing availability and usage. The workshop will serve to inform the 1st part of this recommendation. With regard to the potential for effects. Of UV filters. Thank you very much for listening. I highly recommend that you all review the report. And with special attention to obviously to the effects section, but also to get the context of the of that. Of the that from a human from an ecological risk standpoint from looking at the. The other chapters as well. Thank you very much.