Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation


Polypropylene-based products are commonly used for food preparation and storage, but their capacity to release microplastics is poorly understood. We investigated the potential exposure of infants to microplastics from consuming formula prepared in polypropylene (PP) infant feeding bottles (IFBs). Here, we show that PP IFBs release microplastics with values as high as 16,200,000 particles per litre. Scenario studies showed that PP IFB sterilization and exposure to high-temperature water significantly increase microplastic release. A 21-d test of PP IFBs showed periodic fluctuations in microplastic release. To estimate the potential global exposure to infants up to 12 months old, we surveyed 48 regions, finding values ranging from 14,600–4,550,000 particles per capita per day, depending on the region. We demonstrate that infant exposure to microplastics is higher than was previously recognized due to the prevalence of PP-based products used in formula preparation and highlight an urgent need to assess whether exposure to microplastics at these levels poses a risk to infant health.

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Fig. 1: World market share of PP IFBs.
Fig. 2: IFB sample preparation and establishment and validation of the MP analysis protocol.
Fig. 3: MPs released from PP IFBs.
Fig. 4: Impact of temperature and repeated use on MPs released from three PP IFB products (not including accessories).
Fig. 5: Daily exposure of infants to MP worldwide.

Data availability

All data analysed in this study are contained within the Supplementary Information. The raw data that support the findings of this study are available from the corresponding author upon request to J.J.W. or from the Figshare repository at https://figshare.com/account/home#/projects/88406. Source data are provided with this paper.

Code availability

The mathematical algorithm used for MP exposure assessment has been included in the Methods. The sales data mining software Jungle Scout is available at https://www.junglescout.com/.


  1. 1.

    Thompson, R. C. et al. Lost at sea: where is all the plastic? Science 304, 838 (2004).

    CAS  Article  PubMed  Google Scholar 

  2. 2.

    Efferth, T. & Paul, N. W. Threats to human health by great ocean garbage patches. Lancet Planet. Health 1, e301–e303 (2017).

    Article  PubMed  Google Scholar 

  3. 3.

    Gupta, J. et al. Communicating the health of the planet and its links to human health. Lancet Planet. Health 3, e204–e206 (2019).

    Article  PubMed  Google Scholar 

  4. 4.

    De Sá, L. C., Oliveira, M., Ribeiro, F., Rocha, T. L. & Futter, M. N. Studies of the effects of microplastics on aquatic organisms: what do we know and where should we focus our efforts in the future? Sci. Total Environ. 645, 1029–1039 (2018).

    ADS  Article  PubMed  Google Scholar 

  5. 5.

    Wright, S. L. & Kelly, F. J. Plastic and human health: a micro issue? Environ. Sci. Technol. 51, 6634–6647 (2017).

    ADS  CAS  Article  PubMed  Google Scholar 

  6. 6.

    Meissner, R. Ocean governance for human health and the role of the social sciences. Lancet Planet. Health 2, e275–e276 (2018).

    Article  PubMed  Google Scholar 

  7. 7.

    The Lancet Planetary Health Microplastics and human health—an urgent problem. Lancet Planet. Health 1, e254 (2017).

    CAS  Article  PubMed  Google Scholar 

  8. 8.

    Smith, M., Love, D. C., Rochman, C. M. & Neff, R. A. Microplastics in seafood and the implications for human health. Curr. Environ. Health Rep. 5, 375–386 (2018).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  9. 9.

    Lehner, R., Weder, C., Petri-Fink, A. & Rothen-Rutishauser, B. Emergence of nanoplastic in the environment and possible impact on human health. Environ. Sci. Technol. 53, 1748–1765 (2019).

    ADS  CAS  Article  PubMed  Google Scholar 

  10. 10.

    Cox, K. D. et al. Human consumption of microplastics. Environ. Sci. Technol. 53, 7068–7074 (2019).

    ADS  CAS  Article  Google Scholar 

  11. 11.

    Schwabl, P. et al. Detection of various microplastics in human stool: a prospective case series. Ann. Intern. Med. 171, 453–457 (2019).

    Article  PubMed  Google Scholar 

  12. 12.

    Jin, Y., Lu, L., Tu, W., Luo, T. & Fu, Z. Impacts of polystyrene microplastic on the gut barrier, microbiota and metabolism of mice. Sci. Total Environ. 649, 308–317 (2019).

    ADS  CAS  Article  PubMed  Google Scholar 

  13. 13.

    Lu, L., Wan, Z., Luo, T., Fu, Z. & Jin, Y. Polystyrene microplastics induce gut microbiota dysbiosis and hepatic lipid metabolism disorder in mice. Sci. Total Environ. 631, 449–458 (2018).

    ADS  Article  PubMed  Google Scholar 

  14. 14.

    Mattsson, K. et al. Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain. Sci. Rep. 7, 11452 (2017).

    ADS  Article  PubMed  PubMed Central  Google Scholar 

  15. 15.

    Microplastics in Drinking-Water (World Health Organization, 2019).

  16. 16.

    Oßmann, B. E. et al. Small-sized microplastics and pigmented particles in bottled mineral water. Water Res. 141, 307–316 (2018).

    Article  PubMed  Google Scholar 

  17. 17.

    Schymanski, D., Goldbeck, C., Humpf, H.-U. & Fürst, P. Analysis of microplastics in water by micro-Raman spectroscopy: release of plastic particles from different packaging into mineral water. Water Res. 129, 154–162 (2018).

    CAS  Article  PubMed  Google Scholar 

  18. 18.

    Hernandez, L. M. et al. Plastic teabags release billions of microparticles and nanoparticles into tea. Environ. Sci. Technol. 53, 12300–12310 (2019).

    ADS  CAS  Article  Google Scholar 

  19. 19.

    Geyer, R., Jambeck, J. R. & Law, K. L. Production, use, and fate of all plastics ever made. Sci. Adv. 3, e1700782 (2017).

    ADS  Article  PubMed  PubMed Central  Google Scholar 

  20. 20.

    Tripathi, D. Practical Guide to Polypropylene (Rapra Technology, 2002).

  21. 21.

    Zimmermann, L., Dierkes, G., Ternes, T. A., Völker, C. & Wagner, M. Benchmarking the in vitro toxicity and chemical composition of plastic consumer products. Environ. Sci. Technol. 53, 11467–11477 (2019).

    ADS  CAS  Article  PubMed  Google Scholar 

  22. 22.

    Zhao, S. et al. Analysis of suspended microplastics in the Changjiang Estuary: implications for riverine plastic load to the ocean. Water Res. 161, 560–569 (2019).

    CAS  Article  PubMed  Google Scholar 

  23. 23.

    Pan, Z., Liu, Q., Sun, Y., Sun, X. & Lin, H. Environmental implications of microplastic pollution in the Northwestern Pacific Ocean. Mar. Pollut. Bull. 146, 215–224 (2019).

    CAS  Article  PubMed  Google Scholar 

  24. 24.

    Efimova, I., Bagaeva, M., Bagaev, A., Kileso, A. & Chubarenko, I. P. Secondary microplastics generation in the sea swash zone with coarse bottom sediments: laboratory experiments. Front. Mar. Sci. 5, 313 (2018).

    Article  Google Scholar 

  25. 25.

    Klein, S., Dimzon, I. K., Eubeler, J. & Knepper, T. P. in Freshwater Microplastics—Emerging Environmental Contaminants? 51–67 (Springer, 2018).

  26. 26.

    How to Prepare Formula for Bottle-Feeding at Home (World Health Organization, 2007).

  27. 27.

    Zhao, S., Danley, M., Ward, J. E., Li, D. & Mincer, T. J. An approach for extraction, characterization and quantitation of microplastic in natural marine snow using Raman microscopy. Anal. Methods 9, 1470–1478 (2017).

    CAS  Article  Google Scholar 

  28. 28.

    Simpson, R. J. & Selke, S. E. in Emerging Technologies in Plastics Recycling (ed. Andrews, G. D.) Ch. 18, 232–240 (ACS Publications, 1992).

  29. 29.

    Longo, C., Savaris, M., Zeni, M., Brandalise, R. N. & Grisa, A. M. C. Degradation study of polypropylene (PP) and bioriented polypropylene (BOPP) in the environment. Mater. Res. 14, 442–448 (2011).

    CAS  Article  Google Scholar 

  30. 30.

    Victora, C. G. et al. Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect. Lancet 387, 475–490 (2016).

    Article  PubMed  Google Scholar 

  31. 31.

    Neves, P. A. et al. Infant formula consumption is positively correlated with wealth, within and between countries: a multi-country study. J. Nutr. 150, 910–917 (2020).

    Article  PubMed  Google Scholar 

  32. 32.

    Gallego-Schmid, A., Jeswani, H. K., Mendoza, J. M. F. & Azapagic, A. Life cycle environmental evaluation of kettles: recommendations for the development of eco-design regulations in the European Union. Sci. Total Environ. 625, 135–146 (2018).

    ADS  CAS  Article  PubMed  Google Scholar 

  33. 33.

    Sturm, M. T., Kluczka, S., Wilde, A. & Schuhen, K. Determination of particles produced during boiling in differenz plastic and glass kettles via comparative dynamic image analysis using FlowCam®. Analytik NEWS (14 February 2019).

  34. 34.

    Safe Preparation, Storage and Handling of Powdered Infant Formula: Guidelines (World Health Organization, 2007).

  35. 35.

    Guidance for Health Professionals on Safe Preparation, Storage and Handling of Powdered Infant Formula (Food Standards Agency & Department of Health, 2005).

  36. 36.

    Angulo, F. J., Cahill, S. M., Wachsmuth, I. K., de Lourdes Costarrica, M. & Embarek, P. K. B. Powdered infant formula as a source of Salmonella infection in infants. Clin. Infect. Dis. 46, 268–273 (2008).

    Article  Google Scholar 

  37. 37.

    National Health Service, UK. Infant Feeding Survey—UK, 2010 (NHS Digital, 2012).

  38. 38.

    Breastfeeding and Infant Feeding Practices, Infant Feeding Practices Study II (Centers for Disease Control and Prevention, 2014).

  39. 39.

    Morishita, Y. et al. Distribution of silver nanoparticles to breast milk and their biological effects on breast-fed offspring mice. ACS Nano 10, 8180–8191 (2016).

    CAS  Article  PubMed  Google Scholar 

  40. 40.

    Melnik, E. et al. Transfer of silver nanoparticles through the placenta and breast milk during in vivo experiments on rats. Acta Naturae 5, 107–115 (2013).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  41. 41.

    Gao, X. et al. Effects of developmental exposure to TiO2 nanoparticles on synaptic plasticity in hippocampal dentate gyrus area: an in vivo study in anesthetized rats. Biol. Trace Elem. Res. 143, 1616–1628 (2011).

    CAS  Article  PubMed  Google Scholar 

  42. 42.

    Zhang, C. et al. Induction of size-dependent breakdown of blood–milk barrier in lactating mice by TiO2 nanoparticles. PLoS ONE 10, e0122591 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  43. 43.

    Cai, J., Zang, X., Wu, Z., Liu, J. & Wang, D. Translocation of transition metal oxide nanoparticles to breast milk and offspring: the necessity of bridging mother–offspring-integration toxicological assessments. Environ. Int. 133, 105153 (2019).

    CAS  Article  PubMed  Google Scholar 

  44. 44.

    Oßmann, B. E. et al. Development of an optimal filter substrate for the identification of small microplastic particles in food by micro-Raman spectroscopy. Anal. Bioanal. Chem. 409, 4099–4109 (2017).

    Article  PubMed  Google Scholar 

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This work was supported by Enterprise Ireland (grant number CF20180870), Science Foundation Ireland (grants numbers 12/RC/2278, 16/IA/4462 and 16/RC/3889), the School of Engineering Scholarship at Trinity College Dublin, and the China Scholarship Council (201506210089 and 201608300005). We also thank Keyence for help. The presentation of the material in this publication does not imply the expression of any opinion whatsoever on the part of Trinity College Dublin about specific companies or of certain manufacturers’ products and does not imply that they are endorsed, recommended, criticised or otherwise by Trinity College Dublin in preference to others of a similar nature. Errors and omissions excepted. All reasonable precautions have been taken to verify the information contained in this publication. However, the published material is being distributed without warranty of any kind, either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall Trinity College Dublin be liable for damages arising from its use.

Author information




J.J.W. and L.X. supervised the project and led the overall effort. D.L., J.J.W., J.J.B. and L.X. wrote the manuscript. J.J.B. contributed to the experimental design and validation. Y.S. and D.L. performed online data mining and analysing. D.L., Y.S. and L.Y. carried out the sample preparation. D.L. and J.J.W. carried out the Raman measurements. D.L., D.K.K. and J.J.W. carried out the AFM and scanning electron microscopy characterization. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Liwen Xiao or John J. Boland or Jing Jing Wang.

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Li, D., Shi, Y., Yang, L. et al. Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation. Nat Food 1, 746–754 (2020). https://doi.org/10.1038/s43016-020-00171-y

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