​(10 minute read)

So, what exactly are the best ways to remove stains and rust from your stainless steel bottle?  And what exactly is that oily-looking rainbow color that you sometimes see, and is it harmful?

It honestly gets really confusing, and everyone seems to have their own trick or solution.  So today, let's talk about and test eight of the most commonly-mentioned options to see which are the best for removing stains, rust, and rainbowing in stainless steel water bottles.

You'll see some that work amazing, and others that don't so much at all.  So let's get started and learn how to make your stainless steel bottle look like new.

Given that this is the most common question, we wanted to highlight this answer first by showing the cheapest, fastest, and easiest ways to remove stains and rainbowing from stainless steel mugs and bottles.

Keep reading below to learn more about our tests, as well as which are the best cleaning options for removing rust.

​​​​​​​​​​​​We also cover this info in a YouTube video if you'd prefer to watch the recap that way.

​First, it helps to know the difference between stains, rust, and rainbowing because knowing what you have can change which type of cleaning agent or method you should use.

Sometimes it's hard to tell exactly what's a stain, rust, or rainbowing, especially if it's really bad because maybe there's a combination of these issues.  And even though stains and rainbowing aren't inherently unsafe, they make it more difficult to know if a bottle is truly clean.

For those reasons, it can be a good idea to clean bottles regularly so they look like brand new stainless steel.  These are eight of the most commonly-mentioned methods you'll find online.

• Baking soda
• Vinegar
• Salt and lemon juice
• Bar Keeper's Friend
• Cleaning tablets (like Bottle Bright)
• Bleach
• Abrasive cleaners (like steel wool and Magic Erasers)
• Cleaning beads

​We're going to test some of these three mugs: a rainbowing Corkcicle mug, a coffee and tea-stained Contigo mug, and a stained and rainbowing Hydro Flask 16oz bottle.

​And I don't have any bottles with enough rust to run multiple tests, but I did accidentally left this camping stovetop outside too long, so that'll give us plenty of surface area to test a few different ways to remove rust.

First on the testing block is the Corkcicle with the heavy rainbowing.

Rather than testing one method after another, I taped off four sections inside the mug so we can hopefully see the differences side-by-side against the exact same types of stain.

Made a 1:1 solution of 5% distilled white vinegar with warm water and let that also sit for 10 minutes.​

Made a solution then poured that on, also leaving it for 10 minutes.

Bar Keeper's Friend recommends using it for no more than 1 minute, so I did more of a wipe-on-wipe-off approach over about 30 seconds.

Baking soda and Bar Keeper's Friend had by far the best results of these four methods when it comes to removing rainbowing.  The baking soda results did not look at good as BKF, but that's probably because I did not make as even of coverage with the baking soda paste.  It looked really good in the middle where I know there was good coverage with the paste.

Both the vinegar/water solution and the lemon juice/salt solution did not appear to remove rainbowing much at all.

​Next was Bottle Bright, and for this, I filled the same mug up about halfway with warm water, added a tablet, and let it sit for 10 minutes. (show footage).  You can can how it cleaned some of the mug, but it wasn't as good as I thought it would be.

After that, I tested the Contigo with heavy coffee and tea stains the exact same way using a mug that's been taped into 4 sections.

Again, baking soda and Bar Keepers Friend were great at removing stains, while vinegar and lemon and salt may have removed some of the stains but not nearly as much.

And Bottle Bright worked the same too.  You can see where I filled it halfway up with warm water and let it sit for 10 minutes, but you can really see the difference when used with boiling water and a 30-minute sit time.

Mixed 1 tablet with warm water, then soaked for 10 minutes.

Mixed 1 tablet with hot water, then soaked for 30 minutes and lightly scrubbed with a soft bristle brush.

For good measure, I also cleaned a 16 ounce Hydro Flask bottle.  However, since I'm not able to get my hand inside it, I just used Bottle Bright with hot water, soaked for 30 minutes, then scrubbed it lightly with a brush.  The results speak for themselves!

​Next was the rust test using that camping stove.  I used all of the same methods and durations again, each time just testing one side of this flat part of the stove.

​Made a 1:1 solution of 5% distilled white vinegar with warm water and let that also sit for 10 minutes.​

Test 4 (Rusting): ​Lemon Juice and Salt

Test 4 (Rusting): ​Bar Keepers Friend

Test 4 (Rusting): ​Bottle Bright

I added a Bottle Bright tablet with hot water and let it sit for 30 minutes on the vinegar section because that was the side that still had the most rust.  It didn't seem to do much.

Here were the best results based on visually comparing the different methods.

If you have a stained or rainbowing bottle with a wide mouth that you can get your hand into like a mug or a Stanley tumbler, you may want to try baking soda or Bar Keeper's Friend for stains first because they work really well and are the fastest.  If you can't fit your hand into the bottle, use Bottle Bright with boiling water for 30 minutes, then use a long brush to scrub it and I can almost guarantee that will work.

For rust, try lemon juice and salt first, followed by Bar Keepers Friend.  If your bottle is rusting on the inside and you can't get your hand in there, you can try using lemon juice and salt with a long brush, but it might be difficult to get as much scrubbing force with a brush as much as you really need so you may want to consider replacing your bottle.

Here are some good options for each of the supplies and cleaning methods mentioned.  Big thanks if you use one of the links to buy...it really does help!

Click on any of the images to see the Amazon listing.

There's a reason why I didn't test bleach.  Yes, it will kill any bacteria and remove some stains, but the problem is that bleach is so corrosive that it can damage or remove the chromium oxide layer, which then makes your stainless steel bottle more likely to corrode in the future by rusting.

You'll see a lot of people say they've used bleach for years on stainless steel with no problems, and I'm sure that's true.  If you use a really mild solution and wash it out quickly, then it's probably OK.

​But in my opinion, I'm not sure why you'd want to risk that with a stainless steel bottle when there are other effective stain and rust-removal options like we've just seen that are less likely to cause damage.

It also may not be a good idea to use abrasive things like steel wool.  These can scuff up the surface of the stainless steel, adding more of those microscropic imperfections that make it more likely to stain or corrode again in the future.  It's safer to use something non-abrasive like a brush or sponge with the right cleaning agent.

Magic Erasers are made of melamine (type of plastic) and are essentially a much finer abrasive.  For that reason, we typically still recommend using non-abrasive cleaning methods first, like Bottle Bright with a soft bristle brush.  But if that doesn't work, then Magic Erasers could be worth a try.  Because the melamine is softer than steel and it's much finer, Magic Erasers are much safer to use on stainless steel when you need some extra abrasive force.  However, be careful when using them around painted and powder coated surfaces because it's possibly they could lead to cosmetic damage. 

I've seen these mentioned quite a few times, and they're basically just small stainless steel balls.  They're designed so you can drop them through a narrow neck then shake them around, and the impact from the beads helps remove some of the stains.  I'm not 100% sure, but maybe they just jar some of those tannins loose, and apparently they can work OK and I can see how this would be helpful with something like a rounded wine decanter with a really narrow neck.

But they may not be the best solution for stainless steel bottles.  Even though the beads are small, it's probably hard to get them to clean all the corners effectively, like along the bottom rim of  your bottle.

Also, it sounds like you're meant to use them along with some kind of cleaning solution anyways, so why not just use Bottle Bright and a cleaning brush?

​If you have an extremely narrow neck bottle like a classic S'well, then maybe these cleaning beads could help.  But other than that, I'm not sure they're any better than just using a brush, which you should have for your weekly cleaning anyways.

​If any of you guys have used cleaning beads, I'd be really curious to hear what you think in the comments.

Chances are you've heard the term "PFAS chemicals" or "forever chemicals" within the last few years, but maybe you're wondering what they are.

This article will get you up to speed by covering the most common PFAS-related topics and questions, including:

• What are PFAS chemicals?
• Are PFAS harmful?​
• What does PFAS stand for?
• Where does PFAS come from?
• Why are PFAS chemicals called "forever chemicals?"
• What are the current PFAS thresholds and regulations?
• How does PFAS get into the water supply?
• Which regions of the US have the worst PFAS contamination?
• Are PFAS microplastics?

And importantly, what can you do about it?

• Can PFAS be filtered out of water?
• Which filters remove PFAS?
• Which bottles remove PFAS?

​The term "PFAS" stands for polyfluoroalkyl substances.  It doesn't refer to any single chemical, but rather it refers to a group of thousands of similar ones.  Some of the more common and problematic variations you'll see are PFOS, PFOA, and GenX.

Their unique chemical properties give them noticeable benefits with certain products and applications, particularly with non-stick and stain-free consumer goods.  Because they are inexpensive and have beneficial properties, PFAS chemicals have been used in manufacturing and industry since the 1940s and 50s in all kinds of things, and The most common ones you'll likely hear about are:

• non-stick packaging and cookware
• wrappers and take-out containers from some restaurants
• stain-free clothing and carpets
• factories and industrial sites where products containing PFAS chemicals were manufactured
• firefighting foam that was commonly used at facilities like military bases

Some of these like non-stick cookware and stain-free clothing are easier to avoid, and you're starting to see more products labeled as PFAS-free like the ones shown on PFAS Central's website.  This seems to be leading up to a similar cultural and consumer shift like with what happened in the water bottle industry in the late 2000s with BPAs, which is why nearly every bottle on the market today says they're BPA-free.

And while you may think the products in your home are a more immediate threat, that's not necessarily true.  The areas around or downstream from factories and facilities where PFAS was used often have higher contamination levels in the water supply, which has led to multiple high-profile settlements.  Contamination is very region-specific, so your location plays a big role on whether you likely have increased levels of PFAS in your water supply (which we'll cover in more detail in an upcoming section).

If you're curious to learn more, here is a link to find more information about active PFAS court cases and settlements, including the one with 3M which requires the company to pay at least $10.5 billion in damages.

Perhap the most mindblowing and disturbing thing about PFAS isn't what it is, where it's from, or how it affects you.  Rather, it's how such incredibly small amounts of it can impact your health.  It's is almost impossible to comprehend, but we're going to use the sun to help us out.

​Regulatory agencies limit concentrations of harmful contaminants in your drinking water.  Three common ones you'll see are copper, lead, and more recently PFAS.  The US EPA limits copper at 1.3 parts-per-million ("ppm").  What this means is that if the copper concentration exceeds that limit, sometimes known as an "action level," then the utility provider or the company or person causing the contamination has to take corrective actions as well as notify the public of any potential health concerns.

But 1.3 ppm is hard to visualize, so what does that look like?  For comparison, let's use the sun as a reference.  The sun is on average 93 million miles away, and if you calculate it out, 1.3 millionth of the way to the sun is 121 miles.  That's almost halfway to the orbit of the International Space Station, so it's pretty far.

Lead is even more dangerous, so it has a action level of 150 parts-per-billion ("ppb").  If you calculate THAT out, 150 billionths of the way to the sun is roughly 14 miles up, which is about twice as high as most commercial airplanes.  

But some PFAS chemicals have an action level of 4 parts-per-trillion ("ppt").
(link to EPA presentation with info about limits on pg 10)

To go 4 trillionth of the way to the sun, you don't need a rocket or a plane.  You just need a short ladder because when you calculate it out, 4 trillionths of the way to the sun is about 2 feet.

While it may be difficult to believe, those kinds of small concentrations of PFAS chemicals have been linked to a wide range of health issues, including:

• decreased fertility
• developmental delays in children
• increased risk of some cancers
• interference with your body's natural hormones
• reduced immune system effectiveness
• higher cholesterol

Disclaimer: I do not claim to be an expert on PFAS, and I am relying on published data from reputable sources.  One such source I used is the US EPA, and you can find their PFAS guidelines here.

Now to be clear, this is a developing set of knowledge on a topic that need more research.  Our understanding of what PFAS does to the human body and which concentrations are truly harmful are going to continue evolving based on the evidence, just like all good science.

But there have already been enough peer-reviewed scientific studies from reputable sources that show clear enough negative health impacts to support proposing or enacting some pretty major regulations.

And judging by Google trends and reading headlines about it and multi-billion dollar settlements with major contamination offenders, you're seeing a rise in PFAS awareness with the public which is sure to lead to more changes from brands and manufacturers.

Maybe you've also heard the term "forever chemicals" in recent news, but that's just another name for PFAS.  It's catchier and is better at the reader's attention, so the term is used very frequently in news headlines.  The nickname was coined for two main reasons:

1. PFAS chemicals have bonds between carbon and fluorine atoms, which are some of the strongest bonds found in natural.  This makes PFAS chemicals very stable, long-lasting, and resistant to degradation.
2. PFAS has a cumulative affect.  Because it does not break down easily, the chemicals can stay in your body or the environment for very long time periods, and further exposure continues to increase PFAS levels in your body.

​
So don't be confused: PFAS and "forever chemicals" are the same thing.  One is simply the technical name, and the other is more of a marketing term.

Though it is regulated now, PFAS is in many common products that are still used to this day.  However, in many ways the bigger problem for many people relates to groundwater and the public water supply.

Factories, manufacturing plants, and government facilities that used PFAS either in products manufacturing or things like firefighting foam exposed the environment to PFAS contamination for decades.  Over time, this increased the PFAS concentrations in the soil and groundwater in the immediate area, as well as locations and communities downstream.

Because PFAS chemicals are is so small, many common treatment methods used by public water utilities do not remove it.  And because the threshold like the EPA's 4 ppt limit are so low, it does not take much exposure for a public water utility to technically be over the regulated limit.

Many people have started hearing the terms "PFAS" and "microplastics" recently, and their Google Trends search volumes have risen around roughly the same time period.  As its name suggest, microplastics are small bits of plastic found the water, and increasingly in different parts of the human body.

Both are health concerns that are very widespread in the environment and water systems, making them difficult to avoid.  Also, both can relate to the same types of products, making it even more confusing.

​So should you be worried?  Well, to a large degree that depends on where you live.

The Environmental Working Group has this interactive map that lets you look at sampling data at different points throughout the US.  Darker blue circles are good, lighter blue are bad, purple are military sites which often times have the highest concentrations, and orange are other types of sites like manufacturing plants.

I've included a screenshot of the map below so you can see the overview, but I encourage you to check out EWG's website and interact with the map to zoom in and see sampling data near you.

Of course, most of us can't move to Aspen, so what can we do?

Consumer Notice.org has this really helpful summary of PFAS, and it includes ways you can limit your exposure, mostly focusing on which products to avoid.  When it comes to your drinking water, that's a little trickier but thankfully there are a few options.

Disclaimer: A single PFAS test costs hundreds of dollars because it requires highly senstive and technical tests.  I run a small YouTube channel and blog, so I don't have the money to pay for tests like that yet.  But after researching this and reaching out to companies, here's what I've found.

Not all filters will remove PFAS, so you need to be careful.  ​The below recommendations are based largely on this the Duke University article referenced above and these test results from the Environmental Working Group.

The Environmental Working Group also tested a number of pitchers, which can be a better option for traveling or events.  These two had at least 98% PFAS removal in their testing, and they're some of the lowest-cost ways to start removing PFAS from your drinking water.

Now on this website I mostly talk about water bottles, and they have a place in this discussion too.  Even if you have an under-sink reverse osmosis system, but that doesn't help you out when you're on the road, especially if you're flying somewhere and you can't take any water with you.

So for traveling professionals and road warriors, having a bottle that can help filter out PFAS can be appealing.  Here are a few options that may be worth considering.

Some of these are more conclusively good at removing PFAS, others are easier to use, and some are a lot more affordable.  It's a developing mix of products, but I'm just glad there are some viable options on the market today and there will almost certainly be more coming soon.  If you made it this far, consider using one of the links if you're going to buy one of these products anyways. It doesn't cost you any extra, and I may earn a commission that really helps out. 

Hope this information helps.  Thanks again, and happy hydrating!