Can You Put Boiling Water in A Nalgene Bottle?

One of my favorite backpacking hacks is to fill a water bottle with hot water, wrap it in a sweatshirt, and tuck it into my sleeping bag with me to keep me warm while I sleep. 

I used to do this with a Nalgene Bottle until studies showed that putting boiling water into plastic bottles can be dangerous. 

A lot of people still recommend doing this (and I'm sure a lot of people still do). But should you put boiling water in a Nalgene bottle?

Putting boiling water in a Tritan plastic Nalgene Bottle (the clear versions) won’t cause it to shatter, distort, or melt, but it may cause chemicals to leach from the plastic into your water. Ultralight HDPE Nalgene Bottles probably won’t melt when filled with boiling water, but will soften and can deform easier.

Drinking hot water, or even boiling water that has since cooled, from a Nalgene Bottle may expose you to harmful chemicals and should be avoided.

If you do put hot/boiling water in your Nalgene (eg. to use as a hot water bottle) I recommend discarding the water once it's cooled and washing your Nalgene before refilling it with cool drinking water.

For hot drinks (like coffee) I use stainless steel mugs or drink bottles and don't use plastic bottles.

I stopped using boiling (and even hot water) in my plastic Nalgene Bottles once I took a deep dive into plastic chemical leaching even in the BPA-free era we are currently living in. Why take the risk?

I’ll still sometimes fill one of my Tritan Nalgene Bottles with hot water if I’m in a pinch, but I certainly won’t drink from it again until I’ve washed it thoroughly. 

A stainless steel Nalgene Bottle works just fine and is a much safer alternative. It's also single walled (not vacuum-insulated) so the heat will pass through the walls of the bottle keeping you warm.

Just make sure to wrap it up well because the metal can burn your skin when there's boiling water inside it.

Are Nalgene Bottles Damaged By Boiling Water?

Nalgene bottles won't be damaged physically by boiling water. The regular Nalgene bottles will keep their structure easily and can handle temperatures up to 500ºF (260ºC) before melting whereas the Ultralight Nalgene bottles will get very soft with boiling water so you need to be careful.

If you had to label one brand of plastic water bottle as the tank of the water bottle world it would have to be Nalgene bottles.

Notoriously strong and able to handle extreme punishment Nalgene bottles have been to known to last decades before breaking.

The same is true when the (newer) bottles are exposed to boiling water.

Nalgene Bottles are made of two types of plastic — Tritan plastic and HDPE (sometimes called UVPE) for the Ultralight series. Older Nalgene bottles are made from polycarbonate plastic (which is the plastic that contains BPA).

Tritan plastic Nalgene Bottles can be filled with boiling water without cracking, melting, or deforming thanks to a very high melting point of 500°F (260°C). Read more on the safe temperature ranges of Nalgene bottles.

I personally tried this out and filled up my Tritan Nalgene bottle with boiling water straight out of the kettle.

There was no noticeable change in the softness of the plastic. It still remained extremely hard and didn't deform when I squeezed it. I also noticed I could still pick it up for a few seconds before it became too hot to hold.

So yes, you can safely put boiling water in any Tritan Nalgene bottles. This includes the newer Sustain Tritan Nalgene bottles which are now made from at least 50% recycled plastics.

The ultralight UVPE bottles, on the other hand, have a much lower melting point of 248°F (120°C), and will start to soften at even lower temperatures. 

I personally poured boiling water straight from my kettle into my Nalgene Ultralite bottle. I filled it all the way to the top.

Within just a few seconds the bottle felt soft to touch and I could easily deform the bottle with hands just by squeezing it slightly.

It was a bit troubling as the bottle would stay slightly deformed and would take a few seconds to return to its normal shape. I definitely didn't feel safe having boiling water in this bottle.

Luckily the bottle was not permanently deformed. However, if firm pressure was applied I'm sure it could be bent and deformed in such a way that it would not return to its original shape. SO BE CAREFUL!

I also noticed the Ultralite bottle was much hotter to touch when compared to the normal Tritan bottle.

Though an HDPE bottle is very unlikely to fully melt when filled with boiling water (most boiling water is well below 248°F), it may deform or distort your bottle if pressure is applied to it when it has boiling water inside it.

For old clear Nalgene bottles manufactured before 2008 and made from polycarbonate their response to boiling water will be similar to the newer Ultralight Nalgene bottles. They won't melt, but they will become troubling soft and any firm pressure can cause permanent distortions.

Is It Safe To Drink Hot Water From A Nalgene Bottle?

It’s been shown that single-use water bottles left in the heat can become dangerous to drink from because high temperatures break down the chemical bonds in plastic, causing more chemicals to leach from the bottle into the water. 

But is the same also true for reusable Nalgene Bottles?

Fewer studies have been conducted that show what happens to hot water left in reusable bottles, but those that have been done show that BPA also migrates from reusable bottles at a much faster rate when exposed to heat. 

Granted, Tritan plastic, one of the two plastics modern Nalgene Bottles are made of, was specifically shown not to leach BPA in this study.

According to CTV News Canada:

Scientists from the University of Cincinnati found that when hard plastic drinking bottles were exposed to boiling water, BPA was released 55 times more rapidly and in higher amounts than when they were filled with room temperature water.

But it’s important to consider two things. 

First, Tritan plastic doesn’t contain BPA, which was the only chemical measured in this study. But that doesn’t mean that other chemicals weren’t leached into the water as well. 

And second, many other chemicals found in plastic may be just as harmful as BPA, but haven’t yet been tested for safety. I do a deep dive into whether or not Nalgene bottles are safe to drink out of as well as a detailed explanation of what Nalgene bottles are made of and long story short – the science is inconclusive.

Some studies show that Tritan plastic (what Nalgene is made of) is both BPA free and EA-free (meaning free from other chemicals that leach estrogen). While other studies suggest that they may leach chemicals.

Details on this can be found in my article on whether or not Nalgene bottles are safe.

Overall I think the risk of using boiling water in a Nalgene bottle is very low. I would just discard the cooled boiling water and not drink it and would recommend washing your Nalgene before filling it up with fresh water to minimize potential leaching.

Do I Put Boiling Water In My Nalgene Bottle? (My Opinion)

For me I am pretty cautious when it comes to my plastic water bottles.

I personally don't recommend putting boiling water in a Nalgene bottle. I only put cold or room temperature water in my Nalgene and I discard any water that has been in my bottle for too long or warmed up in the sun.

But I understand many people do put boiling water in their Nalgenes and I think the risk associated with it is extremely low.

If I was to fill up my Nalgene with hot water I would boil water and then allow it to cool slightly to 80-90ºC (175-195ºF) before putting it in my Nalgene bottle to use as a hot water bottle.

I then would NOT drink any of this water. Once cooled I would discard this water and then wash my Nalgene and refill with fresh cool water.

For me stainless steel bottles are a much safer alternative for hot or boiling water.