Abstract
TiO2 and ZnO nanomaterials are widely used to block ultraviolet radiation in many skin care products, yet product labels do not specify their dimensions, shape, or composition. The absence of this basic information creates a data gap for both researchers and consumers alike. Here, we investigate the structural similarity of pigments derived from actual sunscreen products to nanocrystals which have been the subject of intense scrutiny in the nanotoxicity literature. TiO2 and ZnO particles were isolated from eight out of nine commercial suncare products using three extraction methods. Their dimension, shape, crystal phase, surface area, and elemental composition were examined using transmission and scanning electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller (BET) specific surface area analysis, energy dispersive X-ray and inductively coupled plasma optical emission spectroscopy. TiO2 pigments were generally rutile nanocrystals (dimensions ~25 nm) with needle-like or near-spherical shapes. ZnO pigments were wurtzite rods with a short axes less than 40 nm and longer dimensions often in excess of 100 nm. We identify two commercial sources of TiO2 and ZnO nanocrystals whose physical and chemical features are similar to the pigments found in sunscreens. These particular materials would be effective surrogates for the commercial product and could be used in studies of the health and environmental impacts of engineered nanomaterials contained in sunscreens.
Similar content being viewed by others
Notes
We use the term “suncare product” to refer broadly to any product that offers sun protection. Recent trends have made sun protection commonplace in personal care products ranging from shampoo to moisturizer. The term sunscreens is limited to those products whose primary function is to block UV radiation.
We took 8.2 wt% as an average level for sunscreen pigment content that was estimated based on range of weight fraction of TiO2 and ZnO (1.9–14.5 wt%) in sun protection products in four popular retail stores in the US (CVS, Target, Wal-Mart and Walgreens on September 26th and 27th of 2009).
References
Alvarez PJJ, Colvin V, Lead J, Stone V (2009) Research priorities to advance eco-responsible nanotechnology. ACS Nano 3(7):1616–1619
ASTM (2006) Terminology for nanotechnology. E2456-06. American Society for Testing and Materials. www.liu.se. Accessed 15 February 2010
Barker PJ, Branch A (2008) The interaction of modern sunscreen formulations with surface coatings. Prog Org Coat 62(3):313–320
Barnard AS (2010) One-to-one comparison of sunscreen efficacy, aesthetics and potential nanotoxicity. Nat Nanotechnol 5(4):271–274
Brezova V, Gabcova S, Dvoranova D, Stasko A (2005) Reactive oxygen species produced upon photoexcitation of sunscreens containing titanium dioxide (an epr study). J Photochem Photobiol B 79(2):121–134
BSI (2007) Terminology for nanomaterials. Pas 136:2007. British Standards Institution. www.bsigroup.com. Accessed 15 February 2010
Buchalska M, Kras G, Oszajca M, Lasocha W, Macyk W (2010) Singlet oxygen generation in the presence of titanium dioxide materials used as sunscreens in suntan lotions. J Photochem Photobiol A 213(2–3):158–163
Carlotti ME, Ugazio E, Sapino S, Fenoglio I, Greco G, Fubini B (2009) Role of particle coating in controlling skin damage photoinduced by titania nanoparticles. Free Radic Res 43(3):312–322
Colvin VL (2003) The potential environmental impact of engineered nanomaterials. Nat Biotechnol 21(10):1166–1170
Danovaro R, Bongiorni L, Corinaldesi C, Giovannelli D, Damiani E, Astolfi P, Greci L, Pusceddu A (2008) Sunscreens cause coral bleaching by promoting viral infections. Environ Health Perspect 116(4):441–447
Datamonitor (2009a) Personal hygiene/personal care United States industry guide. United States Industry Guide. www.datamonitor.com. Accessed 12 September 2010
Datamonitor (2009b) Suncare global industry guide 2009. www.datamonitor.com. Accessed 12 September 2010
Diffey BL (2001) When should sunscreen be reapplied? J Am Acad Dermatol 45:882–885
Dunford R, Salinaro A, Cai L, Serpone N, Horikohi S, Hidaka H, Knowland J (1997) Chemical oxidation and DNA damage catalysed by inorganic sunscreen ingredients. FEBS Lett 418:87–90
Fairhurst D, Mitchnick MA (1997) Particulate sun blocks: general principles. In: Lowe NJ, Shaath NA, Pathak MA (eds) Sunscreens, development, evaluation, and regulatory aspects. Marcel Dekker, New York
FDA (1999) Sunscreen drug products for over-the-counter human use. Final Monograph No. 98, Federal Register, vol 48
Godwin HA, Chopra K, Bradley KA, Cohen Y, Harthorn BH, Hoek EMV, Holden P, Keller AA, Lenihan HS, Nisbet RM, Nel AE (2009) The university of California center for the environmental implications of nanotechnology. Environ Sci Technol 43(17):6453–6457
Gottschalk F, Sonderer T, Scholz RW, Nowack B (2009) Modeled environmental concentrations of engineered nanomaterials (tio2, zno, ag, cnt, fullerenes) for different regions. Environ Sci Technol 43(24):9216–9222
Gottschalk F, Sonderer T, Scholz RW, Nowack B (2010) Possibilities and limitations of modeling environmental exposure to engineered nanomaterials by probabilistic material flow analysis. Environ Toxicol Chem 29(5):1036–1048
Hansen SF, Michelson ES, Kamper A, Borling P, Stuer-Lauridsen F, Baun A (2008) Categorization framework to aid exposure assessment of nanomaterials in consumer products. Ecotoxicology 17(5):438–447
Hidaka H, Kobaysahi H, Koike T, Sato T, Serpone N (2006) DNA damage photoinduced by cosmetic pigments and sunscreen agents under solar exposure and artificial UV illumination. J Oleo Sci 55:205–1212
ICON (2008) Towards predicting nano-biointeractions: an international assessment of nanotechnology environment, health and safety research needs. International Council on Nanotechnology. http://cohesion.rice.edu/CentersAndInst/ICON/emplibrary/ICON_RNA_Report_Full.pdf. Accessed 06 June 2011
Jiang J, Oberdorster G, Elder A, Gelein R, Mercer P, Biswas P (2008) Does nanoparticle activity depend upon size and crystal phase? Nanotoxicology 2(1):33–42
Johnston HJ, Hutchison GR, Christensen FM, Peters S, Hankin S, Stone V (2009) Identification of the mechanisms that drive the toxicity of tio2 particulates: the contribution of physicochemical characteristics. Part Fibre Toxicol 6:33
Kiser MA, Westerhoff P, Benn T, Wang Y, Perez-Rivera J, Hristovski K (2009) Titanium nanomaterial removal and release from wastewater treatment plants. Environ Sci Technol 43(17):6757–6763
Maynard AD, Aitken RJ, Butz T, Colvin V, Donaldson K, Oberdorster G, Philbert MA, Ryan J, Seaton A, Stone V, Tinkle SS, Tran L, Walker NJ, Warheit DB (2006) Safe handling of nanotechnology. Nature 444(7117):267–269
Montes-Burgos I, Walczyk D, Hole P, Smith J, Lynch I, Dawson K (2010) Characterisation of nanoparticle size and state prior to nanotoxicological studies. J Nanopart Res 12(1):47–53
Moore MN (2006) Do nanoparticles present ecotoxicological risks for the health of the aquatic environment? Environ Int 32(8):967–976
Newman MD, Stotland M, Ellis JI (2009) The safety of nanosized particles in titanium dioxide- and zinc oxide-based sunscreens. J Am Acad Dermatol 61(4):685–692
NNI (2008) Strategy for nanotechnology-related EHS research. Technical report
Nohynek GJ, Lademann J, Ribaud C, Roberts MS (2007) Grey goo on the skin? Nanotechnology, cosmetic and sunscreen safety. Crit Rev Toxicol 37:251–277
Osmond MJ, McCall MJ (2010) Zinc oxide nanoparticles in modern sunscreens: an analysis of potential exposure and hazard. Nanotoxicology 4(1):15–41
Ostrowski AD, Martin T, Conti J, Hurt I, Harthorn BH (2009) Nanotoxicology: characterizing the scientific literature, 2000–2007. J Nanopart Res 11(2):251–257
Popov AP, Priezzhev AV, Lademann J, Myllya R (2005) The effect of nanometer particles of titanium oxide on the protective properties of skin in the UV region. J Opt Technol 73:208–211
Rampaul A, Parkin IP, Cramer LP (2007) Damaging and protective properties of inorganic components of sunscreens applied to cultured human skin cells. J Photochem Photobiol A 191(2–3):138–148
Sadrieh N, Wokovich AM, Gopee NV, Zheng JW, Haines D, Parmiter D, Siitonen PH, Cozart CR, Patri AK, McNeil SE, Howard PC, Doub WH, Buhse LF (2010) Lack of significant dermal penetration of titanium dioxide from sunscreen formulations containing nano- and submicron-size TiO2 particles. Toxicol Sci 115(1):156–166
Sayes CM, Wahi R, Kurian PA, Liu Y, West JL, Ausman KD, Warheit DB, Colvin VL (2006) Correlating nanoscale titania structure with toxicity: a cytotoxicity and inflammatory response study with human dermal fibroblasts and human lung epithelial cells. Toxicol Sci 92:174–185
SCF (2008) Sunscreens explained. Skin Cancer Foundation. www.skincancer.org. Accessed 12 September 2010
Schilling K, Bradford B, Castelli D, Dufour E, Nash JF, Pape W, Schulte S, Tooley I, van den Bosch J, Schellauf F (2010) Human safety review of “Nano” titanium dioxide and zinc oxide. Photochem Photobiol Sci 9(4):495–509
Serpone N, Dondi D, Albini A (2007) Inorganic and organic UV filters: their role and efficacy in sunscreens and suncare product. Inorg Chim Acta 360(3):794–802
Stamatakis P, Palmer BR, Salzman GC, Bohren CF, Allen TB (1990) Optimum particle-size of titanium-dioxide and zinc-oxide for attenuation of ultraviolet-radiation. J Coat Technol 62(789):95–98
Tiano L, Armeni T, Venditti E, Barucca G, Mincarelli L, Damiani E (2010) Modified TiO2 particles differentially affect human skin fibroblasts exposed to UVA light. Free Radic Biol Med 49(3):408–415
Tyner KM, Wokovich AM, Doub WH, Buhse LF, Sung LP, Watson SS, Sadrieh N (2009) Comparing methods for detecting and characterizing metal oxide nanoparticles in unmodified commercial sunscreens. Nanomedicine 4(2):145–159
Wakefield G, Green M, Lipscomb S, Flutter B (2004) Modified titania nanomaterials for sunscreen applications—reducing free radical generation and DNA damage. Mater Sci Technol 20(8):985–988
Wiesner MR (2006) Responsible development of nanotechnologies for water and wastewater treatment. Water Sci Technol 53(3):45–51
Wokovich A, Tyner K, Doub W, Sadrieh N, Buhse LF (2009) Particle size determination of sunscreens formulated with various forms of titanium dioxide. Drug Dev Ind Pharm 35(10):1180–1189
Yu WW, Falkner JC, Shih BS, Colvin VL (2004a) Preparation and characterization of monodisperse PbSe semiconductor nanocrystals in a noncoordinating solvent. Chem Mater 16(17):3318–3322
Yu WW, Falkner JC, Yavuz CT, Colvin VL (2004b) Synthesis of monodisperse iron oxide nanocrystals by thermal decomposition of iron carboxylate salts. Chem Commun 21(20):2306–2307
Acknowledgments
This work was supported by the Center for Biological and Environmental Nanotechnology (EEC-0647452) through NSF, the Shared Equipment Authority instrumentation at Rice University and in part through the collaboration with Consumer’s Union.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Lewicka, Z.A., Benedetto, A.F., Benoit, D.N. et al. The structure, composition, and dimensions of TiO2 and ZnO nanomaterials in commercial sunscreens. J Nanopart Res 13, 3607–3617 (2011). https://doi.org/10.1007/s11051-011-0438-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11051-011-0438-4