Many people are moving away from plastic bottles in the fear it causes cancer. They are moving towards stainless steel bottles like Hydro Flask which are a great alternative to plastic and are more durable than glass or ceramic, which are the other viable alternatives.
But do Hydro Flask bottles cause cancer and are they safe to drink out of?
Hydro Flask bottles are made from kitchen grade 18/8 stainless steel and there have been no studies to suggest stainless steel increase your risk of cancer. Hydro Flask bottles also DON'T use lead for the vacuum seal (other brands do) making them one of the safest stainless steel bottles to drink out of.
I personally wanted to answer this question myself after buying a bunch of Hydro Flask bottles for myself and my kids as well as other brands like Yeti, Klean Kanteen and Thermos (I do run a product review site and YouTube channel after all).
When I couldn't find any information on this I dived into the research to find out exactly what the bottles of made of and what are the chances of each ingredient adding to my risk of getting cancer.
This article is the summary of all I have found.
A lot of this research is the same research I did when I looked into whether or not Yeti tumbler cups cause cancer, with some slight variations as well as a deep look into traces of lead on vacuum insulated bottles.
Can The Stainless Steel In Hydro Flask Bottles Cause Cancer?
Hydro Flask bottles are made out of 18/8 stainless steel (more on what the 18/8 means in a bit).
Some studies have shown that plastic can leech chemicals into your drinks, especially at high temperatures. But can the same thing happen with stainless steel? Can it also leak nasty chemicals into your water or hot coffee?
I'd like to start by saying I'm not a scientist. I'm just a guy who has been drinking out of stainless steel cups for years and I recently bought myself and my kids Hydro Flask bottles and I wanted to do some research to work out if these are safe to drink out of and if they are going to increase me and my kids' chances of getting cancer.
During my research I found quite a few studies on the issue. Nothing specific to Hydro Flask or specific to stainless steel drink bottles. The studies more focused on workers in factories who has concentrated exposure to large amounts of these chemicals, or some minor studies on stainless steel cookware.
I did recently do more research into this when I looked at if you can put lemon in your Hydro Flask. Given lemon is very acidic it is the most likely food to leech metals into your drink.
Still, we can pull some useful information from these studies to help us work out whether or not Hydro Flask or any other stainless steel bottles are likely to cause cancer.
Thankfully the answer is no, they are unlikely to cause cancer.
There is this study, which looked at workers who have been employed in an industry that makes stainless steel.
While the results indicated an increase risk of intestinal cancer in these workers it was impossible to tell if this came from grinding material, grinding agents and chemicals, stainless steel or some other unknown factor.
The result did NOT indicate that dust from stainless steel induces lung cancer. This is different to these findings on workers exposed to high levels of nickel (there is nickel in stainless steel) who did have a greater risk of lung cancer. We'll talk more about this in the section on Nickel.
It's also important through this to remember these are studies on people working in areas with high levels of these chemicals and who are being exposed to a lot of different potentially harmful chemicals. It's not just looking at people drinking from stainless steel bottles.
Do Hydro Flask Bottles Contain Lead?
One of my major concerns with vacuum insulated stainless steel bottles is the fact that lead (yup you heard me right….LEAD!) is used in manufacturing to create and hold the vacuum seal.
Lead, the stuff that is well known to cause all sorts of problems in people and especially children.
In vacuum insulated bottles the lead appears on the outside of the bottle on the bottom and is often covered by a protective layer of stainless steel or plastic. It shouldn't appear on the inside of the bottle at all so you technically shouldn't have any exposure.
Luckily, Hydro Flask moved away from using lead in their bottles back in 2013/14 and developed a proprietary method for creating the vacuum seal without the toxic substance.
This great article by Inc details how it cost the company millions in issues and lost sales to make this a reality and how it was driven by their desire to do the right thing.
They even went to the extent to ensure they was no cross-contamination in their overseas factories that make other stainless steel bottles using the older lead manufacturing system.
So thankfully in any Hydro Flask purchased today you don't have to worry about lead at all.
This is one of the reasons I personally prefer Hydro Flask over any other brand.
Do Hydro Flask Bottles Contain Nickel?
Hydro Flask bottles are made from 18/18 kitchen-grade stainless steel. The 18/8 tells us what percentage of chromium and nickel is in the stainless steel.
Wikipedia tells us that this type of stainless steel contains 18% chromium and 8% nickel.
So this means Hydro Flask bottles do contain nickel, 8% to be exact.
Nickel is actually commonly present in a variety of different foods. This table shows us that food like nuts, chickpeas, soy beans and even dark chocolate actually have high nickel content. Plus even items like meat, eggs and milk contain some nickel.
Can The Nickel in Hydro Flask Bottles Cause Cancer?
From the research I have done I wasn't able to find any studies that linked consuming items from stainless steel products (both bottles like Hydro Flask as well as stainless steel cookware) to an increased chance of getting cancer due to nickel exposure.
“Stainless (steel) is readily attacked by organic acids, particularly at cooking temperatures; hence iron, chromium and nickel should be released from the material into the food”
So it is possible that some nickel (as well as chromium and iron) could be leached into your drink when using your Hydro Flask or any other stainless steel bottle. This would be especially true if you're putting hot beverages like coffee or tea in your bottle.
But remember, most of our nickel exposure will actually come through the food we eat, not the water bottles we drink out of.
Nickel has been proven to increase the risk of lung and nasal cancer in refinery workers who were exposed to high-quantities of the chemical. But again this is NOT looking at drinking from stainless steel but rather inhalation of nickel dust particles or fumes or through direct skin contact with the substance.
I think the most interesting and most relevant information is summed up in this statement that I got from this report:
There is no experimental evidence that nickel compounds are carcinogenic when administered orally or cutaneously.
(Cutaneously relates to the skin as well as orally when it is consumed through the mouth but not inhaled into the lungs)
Nickel Can Cause Allergic Contact Dermatitis
While the nickel in stainless steel doesn't seem to cause cancer, nickel is a well known cause of allergic contact dermatitis (ACD).
This clinical article tells us that people who are sensitive to this type of reaction usually have a predictable localized response when exposed to nickel.
However, the dermatitis can also show up on areas of the body that don't come in direct contact with the nickel.
It states that “stainless steel cookware is another potential dietary nickel source” and that cooking acidic foods can lead to nickel leaching into your foods.
So there is a possibility that Hydro Flask bottles could increase your consumption of nickel and thus potentially create allergic contact dermatitis. It's actually something I am personally exploring with my son and seeing if taking him off the stainless steel bottles will help at all.
Can Chromium in Hydro Flask Bottles Cause Cancer?
Given that Hydro Flask bottles are made from 18% of Chromium is it possible that the chromium in the bottles causes cancer?
Interestingly this report tells us that chromium is a known carcinogen and can increase the right of cancer. But before you freak out and throw out all your bottles this specially relates to “chromium (VI)” or “chromium 6”
But other forms of chromium (eg. “chromium (III)”) are actually essential nutrients that we need.
Let me break this down for you to understand it. Because I had a mini freakout when I saw this information but once you understand it you won't be worried.
Chromium has to be in a “valency state” or 6 in order to be dangerous to humans. The valency state of chromium in stainless steel is 0, therefore isn't dangerous.
If the stainless steel gets corroded then sometimes chromium ions can be released from the alloy. But again don't freak out because even when this happens it's usually the trivalent state (chromium III) which isn't a health hazard.
So it doesn't seem that the chromium in Hydro Flask bottles cause cancer.
Do Hydro Flask Bottles Cause Cancer?
The evidence suggests that NO, Hydro Flask bottles are unlikely to cause cancer or increase your risk of getting cancer.
They may leach some iron, chromium and nickel into your beverage which you will then consume. But this is unlikely to be in quantities large enough to give you and health problems.
In some cases the nickel may cause some people allergic contact dermatitis, so if you're having unknown skin issues then see a specialist and talk to them about it.
So go ahead, fill up your Hydro Flask with confidence and be happy that you're not consuming dangerous chemicals from plastic bottles.
Learn More About Hydro Flask Bottles
Hydro Flask bottles have taken the world by storm and they seem to be everywhere.
Everyone from kids at school to outdoor enthusiasts to bikram yoga instructors are loving these bottles. Click here to learn about why Hydro Flask bottles are so popular.
Hydro Flask aren't the cheapest water bottles out there, in fact they are one of the most expensive brands available.
There are a lot of cheaper options that actually perform better but Hydro Flask are still my favorite because they don't contain any lead. Click here to learn exactly why Hydro Flask bottles are SO expensive.
I love these bottles and it's really good to know that that company has taken the extra step to make sure there are no harmful chemicals in them.
If you're looking for a lead free stainless steel bottle then as far as I am aware Hydro Flask are the only brand that don't use lead in their manufacturing process.