INVESTIGATION 4 which a variety of different active ingredients have been added. Materials Overview In this investigation you will study a cosmetic application of nanotechnology the use of zinc oxide nanoparticles in sunscreens. By the end you will have a good understanding of the range of sunblocks and sunscreens that are available and an idea of which ones you might prefer to use. You will start by making a basic moisturising cream and a piece of UV sensitive jewelry to take home. Then you will study the effect of different materials, including a nano-sunblock on the blocking of ultra-violet (UV) light. This is followed by a general examination of the many different types of chemicals that are found in subscreens and sunblocks. Icebreaker 1: Make a cream Aim In this activity we make a basic cream an emulsion of water, soap and oil. Basic creams form the basis of a variety of different cosmetic and medicinal topical applications and to 1. 100 ml beaker 2. measuring cylinder 3. tripod 4. gauze mat 5. Bunsen burner 6. stirring rod 7. 50 ml paraffin oil 8. LUX flakes 9. few drops of perfume (lavender oil, rose oil etc) Method 1. Place a beaker containing 20mL of water and one level teaspoon of LUX flakes on a gauze mat over a low flame or heat mat. 2. Heat until the soap flakes have melted. DO NOT OVER HEAT. 3. Turn off the burner, leaving the beaker on the hot gauze. 4. Add 50mL of paraffin oil very slowly, stirring the mixture continuously. 5. Remove the beaker to the bench and stir rapidly until the mixture is cool. 6. A glossy white cream will form if you continue to stir until the mixture is cool.
7. Optional - Add a couple of drops of perfume and food colour 8. Store the cream in a labelled brown glass jar to take home. Icebreaker 2: UV sensitive bracelet In this activity you will make a UV light sensitive bracelet or piece of jewelry using UV sensitive beads to take home. Materials 1. UV Sensitive beads 2. Rawhide (cord) Method Count out between 10-20 beads of your choice and thread them onto a piece of rawhide. Wear as a bracelet or necklace. The beads undergo a colour change when exposed to UV light. The colour change is reversed when the beads are kept out of UV light. Icebreaker 3 Normal Zinc vs Nano Zinc Zinc oxide is an excellent UV blockers. However, large particles of zinc also block visible light making sunblockers that use large particulate zinc white or opaque in appearance. Nano sized particles of zinc have the advantage of being transparent to visible light while still blocking UV light. Select 2 types of sunblock that contain zinc oxide one with large particles of zinc oxide; the other with nano-sized particles of zinc oxide. Rub equal sized portions of each sunblock into your skin (do not do this if you have skin that is typically sensitive to creams and lotions). 1. Are both sunblocks easy to rub into your skin? 2. Which sunblock is more opaque after rubbing into your skin? Icebreaker 4 Why use nano-sized zinc particles? Watch the video on nanosunblockers at: www.csiro.au/multimedia/nanotech nology-sunscreen.html
Main Investigation Part A: How well are we protected from Ultra-Violet (UV)? Introduction It is important to protect our skin from damaging UV radiation, but how do we know how well we are protecting ourselves? Is wearing a light shirt at the beach as effective as wearing sunscreen? Is it better protection? Do thicker, whiter sunscreens protect us better than transparent sprays? Can we tell how well something will block UV by looking at its appearance? Aim In this activity you will investigate the following research question: How does the opacity i of a substance relates to its ability to block UV light? Before you start Discuss the following questions and record your answers: 1. Do you think the UV blocking ability of a substance relates to its opacity? Why? 2. Would you expect transparent or opaque substances to be better UV blockers? Why? 3. If you were right, what implications does this have for how you will protect yourself the next time you go to the beach? Materials 1. Variety of different sun blocks, sunscreens, sun gels. Include at least one nano-zinc and one normal zinc sun block. 2. UV light source 3. UV sensitive beads 4. UV bead colour guide 5. Cotton swabs 6. Plastic sandwich bags 7. Black card (A4) 8. Alcohol or alcohol wipes 9. Acetate sheets
Procedure Before starting read through the method and collect all of the materials you will need. Discuss the procedure with a mentor before starting. 1. Choose Your Samples The goal of this lab is to determine if the opacity of a substance relates to its ability to block UV light. Make a choice of items that you think will best help you determine if opacity is related to UV blocking. Tip: Try to choose substances that vary in their opacity and that you would expect to vary in their blocking ability. 2. Judge Their Opacity To make observations about the opacity of the substances you chose, you will be using your eyes as the instruments. 1. Place each substance over a piece of black card. For liquid substances, apply them to a piece of acetate transparency that you can then hold over the black paper. Make visual observations about each sample. How much of the blackness can you see through the sample? 2. Use the Opacity Guide (below) to rank each sample on a 1 to 5 opacity scale. Use 5 to represent complete transparency (you can see all the black through the sample) and 1 to represent complete opaqueness (you can t see any of the black through the sample). Record you observations into the Data Chart. 3. Test Their UV Blocking Ability Since our eyes aren t able to see UV light, you will need to use special UV sensitive beads to test the UV-blocking ability of the substances. You will be provided with three UV bead testers these consist of a single UV bead in an enclosed test-tube. The UV sensitive beads change colour when exposed to UV light; the more UV light they are exposed to, the purpler they become. By
covering the beads with different substances and looking at how much they do or do not change colour, you will be able to see how much (if any) UV light they block. Label one of the UV bead testers C1 for Control 1. This bead will always be kept out of the UV light and will show you the lightest colour that the bead can be. Label another of the UV bead testers C2 for Control 2. This bead will always be exposed to the UV light and should always change colour to let you know that the UV light is reaching the beads. This bead will show you the darkest colour that the bead can be. Label the final tester E for Experimental. You will cover this bead with the different substances to see if they block the UV light. 1. First, use the colour guide to judge the colour of the two control testers (hold the C2 tester under the UV light). Record the numbers on the Data Chart provided. 2. To test each sample, you will need to cover the Experimental Bead with the substance and note its colour. For solids, you can just hold the substance over the bead. Be careful not to confuse the shadow cast by the substance with the colour change of the bead. For liquids, you will need to apply them to a piece of acetate and hold the acetate over the bead while exposing to UV light. Try to apply the same amount of each substance to the acetate piece to get the most accurate results. 3. To judge the colour, hold the colour guide next to the experimental bead to decide what colour most matches the colour of the bead. Record the number for the colour into the Data Chart and then use the following key to assign each substance a UV blocking ability. UV bead colour UV blocking ability 5 4 3 2 1 No blocking Low blocking Medium blocking Key to assign UV blocking ability High blocking Total blocking
Substance name (include SPF if applicable) Appearance (describe) Opacity (1-5 rating) Data Chart Colour of UV bead (1-5 rating) UV Blocking ability Observations and notes
Analysis Analyse your data to see if it helps to answer the research question: Does the appearance of a substance (opacity) relate to its ability to block UV light? One of the ways that scientists organize data to help them see patterns is by creating a visual representation. Below you will see a chart that you can use to help you analyse your data. To fill in the chart, do the following for each substance that you tested: 1. Find the row that corresponds to its opacity. 2. Find the column that corresponds to its UV blocking ability. 3. Draw a large dot in the box where this row and column intersect. 4. Label the dot with the name or initials of the substance. After you have filled in the chart, answer the analysis questions that follow. UV Blocking ability Opacity 5 Fully transparent 4 No blocking (5) Low blocking (2) Medium blocking (3) High blocking (2) High blocking (1) 3 2 1 Fully opaque 1. Now look at the visual representation of your data that you have created and describe what it looks like. Describe any patterns that you see. Remember that seeing no pattern can also give you important information.
2. What pattern would you expect to see if there is a relationship between the opacity of a substance and its ability to block UV light? Draw the pattern by colouring in the grid below. 3. Does your chart match the pattern you would expect to see if there is a relationship between opacity and UV blocking ability? 4. What does this answer mean in practical terms? What does it tell you about well you can judge the effectiveness of sun protection by looking at its appearance? How might this affect your sun protection activities? 5. Do you think that increasing the number of substances you tested would change your answer? Why or why not? 6. How did the nano-zinc compare to the other materials you tested? In particular, how did it compare to the normal zinc? 7. Did you encounter any difficulties in comparing different sunblock products using the method above?
Main Investigation Part B: Sunscreen Ingredients Activity Most of us (hopefully) apply sunscreen to protect us from the sun when we are going to be outside for a long time. But how many of us have ever stopped to read the bottle to see what we are putting on our bodies? What kinds of chemicals are used to block the sun rays? Do different sunscreens use different ingredients to block the sun? How might the different ingredients used affect us? In this activity you will take a look at several sunscreens to see what we are putting on our bodies when we use these products. Materials Different bottles of sunscreen, including: One sunscreen with a high SPF (30-50). One sunscreen with a low SPF (5-15). One sunscreen designed for skiers or surfers One sunscreen for sensitive skin or babies. One sunscreen that has zinc oxide (ZnO) or titanium dioxide (TiO2) as an ingredient. Instructions Look at the back of one of the bottles. You should see a list of the active ingredients in the sunscreen. These are the ingredients that prevent sunlight from reaching your skin ( inactive ingredients are also added to influence the appearance, scent, texture and chemical stability of the sunscreen.) Also look to see what kind of protection the sunscreen claims to provide. Does it provide UVB protection? UVA protection? Does it claim to have broad spectrum protection? What is its SPF number? Does it make any other claims about its protection? Record your observations for each sunscreen in the data chart and then answer the questions that follow.
Data chart Brand 1 Active Ingredients SPF UVA? UVB? Broad spectrum? Price 2 3 4 5
Questions 1. How many different active ingredients did most of the sunscreens have? 2. What were the most common active sunscreen ingredients you saw? Are these organic or inorganic ingredients? 3. Did any of the sunscreens you looked at have active ingredients that were very different from the rest? If so, what were they? 4. Were you able to find a sunscreen with inorganic ingredients in it? If so, which one(s) contained them? 5. How many of your sunscreens claimed to have UVA protection? UVB protection? Broadband protection? 6. Why do you think that many sunscreens have more than one active ingredient? Why can t they just put in more of the best one?
Main investigation Part C: Newspaper Article Read through the following article: Big issues with small science: nanotechnology From: The Australian March 27, 2010 By: Leigh Dayton, Science Writer It was all happening this month in the Paris of the south. As designer-clad models strutted down the catwalks, celebrities smiled, cameras flashed, fashionistas dispensed air kisses and protesters waved placards. Protesters? At the 2010 L'Oreal Melbourne Fashion Festival? Indeed so. Environmental group Friends of the Earth was out in force, targeting cosmetic giant L'Oreal for incorporating nanoparticles in its up-market products. According to FOE spokeswoman Georgia Miller, the world's largest purveyor of posh potions and lotions is also the top nanotechnology patent holder in the US and that's cause for concern. "The problem is, more and more scientific research is emerging that nanoparticles commonly used in cosmetics and sunscreens could present serious new health and environmental risks," Miller says. "For over five years FOE has called for a halt to sales of nano-products until legal gaps are closed and regulations are introduced to ensure safety and public choice." That's just what the commonwealth is doing, says Craig Cormick, manager of public awareness and community engagement for the National Enabling Technology Strategy. Launched last month by Science and Innovation Minister Kim Carr, the $38.2 million strategy is designed, in part, to untangle the jumble of laws, agencies and legal complexities surrounding regulation of nanotechnology, the manipulation of particles measuring from one nanometre -- one millionth of a millimetre -- to about 100 nanometres in size. As Carr noted, the technology of the tiny holds huge promise for advances in areas as diverse as building materials, future fuels, computing, medicine, agriculture, food and, of course, cosmetics: "Nano-products will be worth trillions in the years ahead."
Still, scientists such as Nobel-prize-winning Swiss physicist Heinrich Rohrer, a pioneer of nanotechnology, worry that materials behave differently at the nano-scale than they do in the real world. "We just don't know the risk," he cautions. Despite the health and safety uncertainties, nano-products continue to hit the international market without rigorous scientific scrutiny. Two years ago FOE identified 104 foods, food packaging and agricultural products containing nanomaterials on sale worldwide. Today the tally is undoubtedly far higher. This is happening as regulators struggle to keep pace, unsure about how to ensure these products are safe, says Karinne Ludlow, an expert in science, technology and the law at Melbourne's Monash University. "It comes back to the lack of science. We don't have the data to regulate. We don't have safety and measuring capabilities." Then there's the question of who should be responsible for the data and ensuring the safe use and sale of nanomaterials and products. In 2007, Ludlow and two Monash colleagues reviewed the possible effects of nanotechnology on Australia's regulatory rules of the road. They concluded that 10 federal agencies and one state environment agency have responsibilities touching on nanotechnology or nano-products. Between them those agencies oversee 59 "relevant legislative instruments", including acts, regulations, guidelines, codes and standards. "Clearly, you can't just sit and wait," Cormick comments, adding that the new enabling technology strategy builds on recommendations from the Monash report and succeeds the 2008 National Nanotechnology Strategy. But instead of establishing a single nano-regulator - - "That would be very, very hard" -- he says the plan is to keep Australia's existing regulatory framework in place while requiring individual agencies to review and revise activities as new data, monitoring tools and challenges emerge. Regulators at the nano-frontline are Foods Standards Australia New Zealand, the Therapeutic Goods Administration, the Australian Pesticides and Veterinary Medicines Authority and the National Industrial Chemicals and Assessment Scheme (NICNAS). FSANZ was off the mark in 2008 with its call for food companies to disclose if new products they want registered contain nano in the food or packaging. According to physician, lawyer and nanotechnology expert Tom Faunce, the TGA and APVMA are lagging behind, while NICNAS races along, already having posted online proposals for regulating nano-materials.
He speculates that's so as NICNAS has more "real world" experience. For instance, it issued voluntary calls to Australian industry in 2006 and 2008, asking for information on uses and quantities of nanomaterials manufactured or imported. "It was a complete failure. None of the manufacturers reported," says Faunce, an Australian Research Council Future Fellow based at the Australian National University. He goes further, suggesting Carr's new strategy is also failing to deliver. He argues the strategy's regulator review process is all well and good but too slow. Faunce cites five classes of nanomaterials which, a growing body of evidence suggests, warrant immediate action: nanoparticles in cosmetics; anti-bacterial silver nanoparticles used in cleaning products and even clothing; nanoparticles of zinc oxide in sunscreens; cerium oxide nanoparticles in fuels; and titanium dioxide nanoparticles in some sunscreens. Faunce and Cormick say Australian researchers are contributing to an Organisation for Economic Co-operation and Development project to crank out solid data on these and other classes of nano-materials. And at last month's International Conference on Nanoscience and Nanotechnology in Sydney, Faunce called for swift application of the data, going on the better-safe-than-sorry precautionary principle. "We have to regulate." Meanwhile, the strategy roll-out continues apace. Carr will announce members of stakeholder and advisory groups "in the near future". Officials are considering public consultations and facilities for measuring and assessing all things nano while regulators ponder regulations. Little wonder Miller expects to be attending fashion festivals for years to come.
Research Questions 1. What concerns do Friends of the Earth have about the use of nanoparticles in beauty products? 2. Are nanoproducts regulated in Australia? 3. Is it compulsory to specify on the label when products contain nanotechnology? Should it be? 4. How important is science to the establishment of a nanotechnology regulatory body? www.cancer.org.au/cancersmartlifestyle/sunsmart/nanoparticles_sunscreen.htm
i Opacity Opacity describes how easy it is to see through a substance ie. how transparent it is. A completely opaque substance cannot be seen through it at all. Opacity is a separate property than the colour of a substance. For example, you can have something that is yellow and transparent like apple juice; or something that is yellow and opaque like cake frosting.