Which Water Bottle Material is the Safest? (7 Materials Ranked) (2024)

Update March 9, 2024: For more info about lead and Stanley bottles, see our more recent post here.

A common question that many people ask when buying a reusable water bottle is, will this bottle be safe to drink from every day? It's important to know that your bottles are safe for you and your family to use, so in this video, we are going to take a closer look at seven types of water bottle materials:

• plastic
• stainless steel
• glass
• aluminum
• copper
• silicone
• titanium

Our goal is to give you a better understanding of the available options on the market today so you can make the best decision for your situation. We'll review which ones are generally considered to be the safest, and which ones you may want to avoid.

(Rankings are at the end)

Before we even talk about any water bottle materials, we need to talk about cleaning. Any bottle that isn’t cleaned regularly will eventually become unsafe to drink from due to bacteria buildup. In an ideal world, you should wash your bottle after every single use, but that’s not practical for a lot of people and situations. At the very least though, you should try wash your bottle thoroughly at least every 2-3 days if you use it each day . Using a brush kit like this one is really helpful to clean larger water bottles, especially narrow mouths. It’s also a good idea to give your bottle a deep clean every few weeks with a cleaning tablet, and I found that Bottle Bright’s tablets worked great to get stains out of my coffee bottle.

We also recommend that you do not use bleach with your bottle. With some bottles, like 304 stainless steel, bleach can corrode the metal and cause damage. Just clean your bottle regularly with warm, soapy water and use a bottle cleaning tablet every week or two for a deeper clean and you’ll be good.

​The main concern that usually comes up when talking about water bottle materials and health is leaching, which is when chemicals or toxins from the bottle seep into the drink. It’s the same process that created a widespread fear tomatoes in the 1700s when many people thought they were poisonous, as explained in more detail in this article by Reader's Digest.

Of course the tomatoes themselves weren’t toxic, but the acid from the fruit would leach lead from the pewter plates and utensils, causing lead poisoning. More recently, BPAs have received most of the headlines, which leads us into our first material, plastic.

Plastic is the most commonly used material today for water bottles for several reasons, including how it’s inexpensive, easily manufactured, and extremely durable.When it comes to concerns with reusable plastic bottles, you’ve no doubt heard about bisphenol A compounds, more commonly known as BPAs. These are widely used in industrial and consumer goods, but they have also been associated with adverse health effects in many studies. One of the primary concerns is that BPA can mimic the effects of estrogen on your body, which can lead to hormone imbalance, but there are other potential health concerns as well.

To be clear, the risk is not completely known. Researching any kind of low-dose, long term exposure like with BPAs is difficult, and there is some uncertainty on how of a risk BPAs actually pose for most people. With over 17,000 scientific papers on PubMed as of 2023, there is understandably a mix of results. And in fact, many studies indicate that most BPA exposure is so small that it is not a significant risk for the majority of people. However, there is enough evidence and uncertainty that’s led to most public health agencies taking steps to reduce BPA use, especially in products intended to be used with infants. For example, in 2012, the EPA officially amended its regulations to no longer allow BPA use in baby bottles and sippy cups.

Given all these changes and public knowledge about BPAs today, you’d be hard-pressed to find a reusable plastic bottle on the market that isn’t BPA-free, but it doesn’t hurt to check. Just look on the product listing or on the packaging for the phrase “BPA-free.” And if you have an older plastic bottle that you’re not sure about, you might want to consider buying a replacement.

In general, it’s a good idea to stick to Tritan bottles if you’re going with plastic. This type of material is really light, so it’s for hiking when you want to minimize how much weight you’re carrying. Nalgene and CamelBak have some tried-and-true bottles to choose from, and YETI recently released their Yonder series plastic bottle.

To go a step further down the steel rabbit hole, not all stainless steels are the same. The most common types you’ll see associated with water bottles are 304, 316, 18-8, and 18-10. I won’t get into the details here about these different grades, and honestly it can get a little confusing because there is some overlap between the classifications.

You’ll most commonly see 304 or 18-8 listed in the product descriptions for stainless steel water bottles. Technically, 316 is better than 304 and 18-10 is better than 18-8 and, so if you’re really looking for the best-of-the-best, go with one of the higher grades. For example, 316 steel is more resistant to corrosion in salty environments, making it a better steel for marine construction projects that will be in and around salt water.

​But when it comes to water bottles for average consumers, it doesn’t make a practical difference which grade you go with. Any of these four stainless steel alloys are recognized as food-safe.

Many people who want to avoid plastic contacting their water buy a stainless steel bottle and assume they are good, but the reality is that most water bottles still have exposed plastic under the lid that can come in contact with your drink. Don’t forget to check under the lid if you’re looking to have completely free plastic drinking.

To my knowledge, all of YETI’s lids have plastic on the bottom. Hydro Flask’s standard lids have plastic on the bottom, but they sell a replacement lid with stainless steel. Klean Kanteen’s TKWide insulated bottles have plastic on the bottom of the lids, but I’ve included a link in the description to two of their bottle options that have stainless steel under the lid.

​Safety with water bottles isn’t just related to what you ingest, and with glass, there is always a concern that it could break and create sharp edges. This is especially a concern for children. Glass is already pretty heavy and bulky, and it’s not hard to imagine a scenario where a child is running with a water bottle in his or her hand and trips. The natural reaction is to put your hands out in front to break your fall, and it could lead to some nasty cuts if the bottle breaks in your kid’s hands.

It's worth noting that most glass bottles on the market are made with a specific type of glass called borosilicate. You may not have heard of this specific term before, but odds are that you’ve used this type of glass at some point. Pyrex is one of the most well-known borosilicate glass brands. This type of glass is more resistant to temperature changes and shock, so it’s less likely to crack or chip. In addition, many glass bottle brands manufacturers also sell their glass bottles with a protective silicone sleeve. So yes, this type of bottle is still more susceptible to breaking in a way that could be dangerous compared to plastic or stainless steel, but the combination of borosilicate glass and the silicone sleeve helps prevent this from happening in most situations.

​Copper is a newer option that you can find on the market today, like this one from the brand Milton that was released in 2020. From what we’ve read, copper is a double-edged sword.

On the good side, they look really cool, and there is some evidence that the copper can kill bacteria and microbes in water.

Some brands list additional health claims, including how copper is “known for its anti-oxidant, brain-stimulator and immunity booster properties.” However, as far as I can tell, this is dubious at best and is not backed up by trusted sources. In fact, too much copper intake can lead to symptoms like nausea, dizziness, and abdominal pain.

​Take this paper Q&A sheet from the Washington State Department of Health. It discusses the negative effects of ingesting water that’s been in contact with copper for too long, mostly involving old copper pipes. They recommend running water in copper pipes for a minute before using it, and whenever possible, use cold water only because hot water dissolves more copper.

To be fair, this paper is referring primarily to old copper pipes that are used in construction, and I wouldn't be surprised if the high-grade copper that is allegedly used in many water bottles today is safer, especially because it's easier for you to clean and maintain it.

However, there are other similar options like stainless steel that are generally accepted to be safer, so in my opinion, why take the risk?

​Quick note about silicone. There are silicone types that are not food-safe, and it’s typically when fillers used do not have the same food-safe properties.

You might also read about a “pinch test” to verify if the silicone is safe. The thought is that if you pinch silicone and it turns white, this indicates it has fillers that can be unsafe. However, this is not necessarily true, and the pinch test is more of a myth from what I have read.

There are food-safe silicone products that turn white when pinched but that are still perfectly safe. When buying a silicone product, make sure it says it’s FDA-approved, food-grade, or food-safe silicone, and if you have any questions, reach out to the manufacturer.

No, silicone does not contain BPAs. This article does a great job at explaining more of the details and information about silicone and how it's different and generally considered to be safer than plastic. And the Canadian government writes that there are no known health hazards. In the most basic terms, silicone uses silica, aka sand, which is the same primary component as glass. This avoids some of the more problematic polymers and compounds found in plastics.

Having said that, silicone is obviously very synthetic and is relatively new-to-market compared to an alternative like glass. For that reason, I wouldn't fault you if you chose to avoid an all-silicone bottle for now until more research is completed.

But for all of that functionality, you can expect to pay a much higher price. The cheapest titanium bottle option we found is $80, and other options easily get up over triple digits. In short, titanium bottles appear to be one of, if not the, best material options available for water bottles, but they have a price point that reflects the premium nature of this material.

​One other downside worth mentioning is that there does not appear to be a dual-wall vacuum insulated option like you’ll find with so many stainless steel bottles. Some brands like Boundless try to spin this as a positive because you can put your bottle directly on a stove to boil water for cooking or to purify it, and for sure this is a benefit when camping or hiking long distances. But for most people, they just want a bottle that can hold ice for 4-8 hours, and I’m not sure a titanium bottle is a good option for that unless you get a thermal sleeve.

And finally, the safest materials to use are stainless steel, silicone, titanium, and glass. From what I’ve read, these bottles all have consistent safety testing results, and you should feel safe and confident using any of them.

*Silicone is newer and more closely related to plastic, so I wouldn't fault you if you wanted to avoid this type of bottle until more research is done. I almost ranked it in Tier 2 for that reason.

**Glass would be at an even higher level if it weren’t for concerns with breakage and cutting yourself. But if you’re really looking for the cleanest, most natural drinking option, glass is probably the best material to go with.