At mymizu, we’re often asked, “Is it really safe to drink tap water in Japan?” It’s a common concern, but here’s the reality: Japan’s tap water is among the safest in the world!

In fact, mymizu was created to encourage people to make better use of Japan’s clean, safe tap water.

In this blog, we’ll cover:
1️⃣ Why Japanese tap water is safe and beneficial,
2️⃣ Tips for making tap water taste even better, and
3️⃣ How we can all contribute to a sustainable future.

Much of the data and other information in this article is provided by Cleansui, a trusted leader in water purification technology.

Our strategic partner: Cleansui

Since 2021, mymizu has been proudly partnered with Mitsubishi Chemical Cleansui Corporation. Together, we’re working to reduce single-use plastics and promote sustainable lifestyles.

Our goal is to raise awareness about the safety of Japan’s tap water while encouraging more people to embrace the habit of using reusable bottles.

Is tap water safe to drink in Japan?

Japan maintains exceptionally high standards for water quality

Japanese tap water must meet 51 rigorous standards under the Waterworks Law, ensuring its safety and cleanliness. Surprisingly, this is far more than the 18 standards required for bottled mineral water. So yes, tap water in Japan is not only safe, but also held to higher standards than most bottled options!

Japanese tap water is renowned as some of the safest in the world. Thanks to stringent regulations and meticulous management, the water supplied to households is of exceptional quality—clean, safe, and dependable for all to enjoy.

Where does tap water come from?

Tap water, like mineral water, originates from natural sources such as rivers and mountains. In many cases, the sources for tap water and mineral water are the same. Tap water also contains natural minerals, though the type and quantity can vary by region. Exploring the unique composition of tap water in your area can be both fascinating and insightful!

Tap water plays a vital role in the natural water cycle. After use, it undergoes treatment at sewage plants, where specialized microorganisms break down and remove contaminants. Once purified, the water is released back into rivers or oceans, seamlessly reentering nature’s cycle.

Some mymizu refill spots provide access to fresh spring water, offering a truly unique experience. It's a chance to refill your bottle while also appreciating nature's gifts!

Concerned about PFAS in tap water?

PFAS (per- and polyfluoroalkyl substances) are chemical compounds that have raised concerns due to their presence in tap water and potential health risks. Valued for their heat resistance and water-repellent properties, PFAS have been widely used in everyday products like food packaging. However, these chemicals are incredibly persistent, breaking down slowly and accumulating in the environment over time. Studies suggest they may pose health risks, including impacts on the immune system and potential links to cancer.

In Japan, local governments regularly conduct strict water quality tests to monitor PFAS levels. To help the public stay informed, NHK has released a “Tap Water PFAS Detection Status Map” showing the latest regional data and historical maximum values. Check it out to learn more!

Easy ways to enhance the taste and safety of your tap water

Concerned about the chlorine or chalky taste in your tap water? With a few simple steps, you can enhance its safety and enjoy a cleaner, fresher flavor.

Types of Water You Can Refill at Stores: Purified & Hot Water

Boiling

Boiling tap water for 10–15 minutes can remove harmful substances like trihalomethanes while also reducing chlorine and chalky odors.

Here’s a fun fact: over 860 of mymizu’s refill partners provide free hot water! Why not take advantage of this and refill with hot water on the go? It’s ideal for making tea or coffee, or simply staying warm during the colder months.

Using a water purifier

A water purifier offers a quick and convenient way to eliminate chlorine and impurities from your water. Whether you need a portable option or one that attaches directly to your sink, there are plenty of solutions to suit your needs.

Help reduce plastic waste

Choosing tap water over bottled water helps reduce plastic waste and aligns with mymizu's mission of creating a more sustainable, water-conscious world. It also minimizes the risk of consuming microplastics, which are commonly found in bottled water. Every small switch to tap water makes a difference—cutting plastic waste and reducing CO₂ emissions by more than 90%.

The future of water: What we can do

With the climate crisis intensifying, the depletion of water resources has become an urgent issue. Water is a finite resource, and even the smallest actions can make a meaningful difference in preserving it. Here are a few simple steps you can take today to help safeguard the future of water:

Conserve water

Limit laundry and dishwashing to fewer cycles.
Take shorter showers and avoid letting the water run unnecessarily.
Repurpose leftover bathwater for washing clothes.

Prevent water pollution

Wipe away grease from dishes before washing them.
Use drain baskets to catch food scraps and prevent them from going down the drain.
Reduce the amount of detergent and shampoo you use.

Conserve natural water

Avoid disposing of trash in rivers, waterways, or on streets.
Join community efforts such as beach cleanups and other volunteer initiatives to help protect the environment.

A sustainable future starts with small, everyday actions—and carrying your own bottle while drinking tap water is a great place to begin. In Japan, tap water is not only safe but also environmentally friendly. If you know someone hesitant about drinking tap water, we encourage you to share this blog article with them! Together, we can continue to learn, research, and take steps toward a more eco-conscious lifestyle.

mymizu, in collaboration with Cleansui, remains committed to creating a world where access to clean water is a fundamental part of everyday life. Thank you for reading til the end, and happy refilling!

Read Cleansui's original article here. (Japanese only)

Tap Water in Japan: Is It Really Safe?