Science, Tech, Math › Science Is Rain Water Clean and Safe to Drink? Share Flipboard Email Print PeopleImages / Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated February 18, 2020 Have you ever wondered whether or not it's safe to drink rainwater? The short answer is: sometimes. Here's a look at when it's not safe to drink rainwater, when you can drink it, and what you can do to make it safer for human consumption. Key Takeaways: Can You Drink Rain? Most rain is perfectly safe to drink and may be even cleaner than the public water supply. Rainwater is only as clean as its container. Only rain that has fallen directly from the sky should be collected for drinking. It should not have touched plants or buildings. Boiling and filtering rainwater will make it even safer to drink. When You Shouldn't Drink Rain Water Rain passes through the atmosphere before falling to the ground, so it can pick up any contaminants in the air. You don't want to drink rain from hot radioactive sites, like Chernobyl or around Fukushima. It's not a great idea to drink rainwater falling near chemical plants or near the plumes of power plants, paper mills, etc. Don't drink rainwater that has run off of plants or buildings because you could pick up toxic chemicals from these surfaces. Similarly, don't collect rainwater from puddles or into dirty containers. Rain Water That Is Safe for Drinking Most rainwater is safe to drink. Actually, rainwater is the water supply for much of the world's population. The levels of pollution, pollen, mold, and other contaminants are low — possibly lower than your public drinking water supply. Keep in mind, rain does pick up low levels of bacteria as well as dust and occasional insect parts, so you may want to treat rainwater before drinking it. Making Rain Water Safer Two key steps you can take to improve the quality of rainwater are to boil it and filter it. Boiling the water will kill off pathogens. Filtration, such as through a home water filtration pitcher, will remove chemicals, dust, pollen, mold, and other contaminants. The other important consideration is how you collect rainwater. You can collect rainwater directly from the sky into a clean bucket or bowl. Ideally, use a disinfected container or one that was run through a dishwasher. Let the rainwater sit for at least an hour so heavy particulates can settle to the bottom. Alternatively, you can run the water through a coffee filter to remove debris. Although it isn't necessary, refrigerating the rainwater will retard the growth of most microorganisms it could contain. What About Acid Rain? Most rainwater is naturally acidic, with an average pH of around 5.0 to 5.5, from the interaction between water and carbon dioxide in the air. This is not dangerous. In fact, drinking water rarely has a neutral pH because it contains dissolved minerals. Approved public water could be acidic, neutral, or basic, depending on the source of the water. To put the pH into perspective, coffee made with neutral water has a pH around 5. Orange juice has a pH closer to 4. The truly acidic rain that you would avoid drinking might fall around an active volcano. Otherwise, acid rain isn't a serious consideration. Additional References Joan D. Willey; Bennett; Williams; Denne; Kornegay; Perlotto; Moore (January 1988). "Effect of storm type on rainwater composition in southeastern North Carolina". Environmental Science & Technology. 22 (1): 41–46. doi:10.1021/es00166a003 Joan D. Willey; Kieber; Avery (2006-08-19). "Changing Chemical Composition of Precipitation in Wilmington, North Carolina, U.S.A.: Implications for the Continental U.S.A". Environmental Science & Technology. 40 (18): 5675–5680. doi:10.1021/es060638w S. I. Efe; F. E. Ogban; M. J. Horsfall; E. E. Akporhonor (2005). "Seasonal Variations of Physico-chemical Characteristics in Water Resources Quality in Western Niger Delta Region, Nigeria" (PDF). Journal of Applied Scientific Environmental Management. 9 (1): 191–195. View Article Sources "Rainwater Collection.” Centers for Disease Control and Prevention, 18 July 2013. “Can You Drink Rain Water - Is Rainwater Safe to Drink.” Surviving Guide, 19 Nov. 2019. "Acid Rain." Environmental Protection Agency. Reddy, Avanija, et al. "The pH of Beverages in the United States." The Journal of the American Dental Association, vol. 147, No. 4, April 2016, pp. 255–263, doi:10.1016/j.adaj.2015.10.019 Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "Is Rain Water Clean and Safe to Drink?" ThoughtCo, Oct. 29, 2020, thoughtco.com/can-you-drink-rain-water-609422. Helmenstine, Anne Marie, Ph.D. (2020, October 29). Is Rain Water Clean and Safe to Drink? Retrieved from https://www.thoughtco.com/can-you-drink-rain-water-609422 Helmenstine, Anne Marie, Ph.D. "Is Rain Water Clean and Safe to Drink?" ThoughtCo. https://www.thoughtco.com/can-you-drink-rain-water-609422 (accessed April 16, 2021). copy citation Watch Now: Why is Water So Crucial to Body Function?