Sustainable cold storage in the lab: Ready to reduce costs and environmental impact?

Would you also like to promote sustainability in your lab this year, but you’re not sure exactly where to start? 

Laboratories are extremely energy-intensive – in fact, the only industrial space using more energy per square meter is that of data storage centres! One of the reasons for the massive energy consumption is the use of cold storage; our multitude of fridges and freezers is really taking a toll on the planet. That’s why it makes a real difference – in terms of environmental impact as well as costs – when you adopt greener cold storage habits. So how do you do that?

My name is Nikoline Borgermann – a green lab consultant at Ava Sustain – and here’s what I would do!

Join the Freezer Challenge

The Freezer Challenge is an international cold storage competition for laboratories – and it’s a great way to develop more sustainable cold storage habits!

Thousands of laboratories from 195 countries are participating in this yearly sustainability initiative organised by the two non-profit organisations My Green Lab and The International Institute for Sustainable Laboratories (I2SL). In the course of six months, labs are optimizing their cold storage management to reduce energy consumption, costs and environmental impact – and to promote sample integrity and accessibility.

They do this by taking various energy-saving actions which they report in simple score sheets. At the end of the competition, labs and institutions are scored, and the winners are published and acknowledged in Nature and at the yearly I2SL conference. (Yes, you got it right: there’s a way to get your name in Nature even if you are not working on a ground-breaking research project!)

Intrigued? Continue reading to get an overview of the point-giving actions which fall into the following four categories:

Good Management Practices

This category includes defrosting and decluttering of freezers & fridges as well as exploiting the space to the fullest. The higher density of samples, the less fridges and freezers will be needed! Importantly, this category also includes the action of inventorying samples. Messy freezers are not only extremely annoying; they are also not very green. Remember that every time you open a freezer door, the temperature inside increases, and the freezer will consume energy to cool down again. This means: the more you open the door and the longer you keep it open, the more energy will be consumed. A great way to save energy, time and frustrations is therefore to have print-outs of freezer contents indicating precise locations on the freezer door so you can locate your object of interest before actually opening the door. Also, store the things you use most frequently in a place where they are easy to retrieve!

I would be lying if I said it’s a quick fix to organize and take inventories of your freezers and fridges. But I guarantee you: the time and effort you put into it will come back multiplied. It’s so much easier to work in a lab when you know exactly what you have and where to find it! With people joining and leaving the lab continuously, the risk of items going missing is high – unless you have detailed and up-to-date overviews of what you have and where it is. I can’t count how many times I have been searching for stuff in the wrong drawers and boxes (or even the wrong freezers!) and how many times I have had to commute between various offices and the lab before I finally found someone who knew the location of whatever reagent or sample I needed. Boy, have I cursed over unorganised freezers during my years in the lab!

Temperature tuning

This second category of the challenge includes the action of chilling up your -80°C freezers to a set temperature of -70°C. Does this sound too crazy or risky to you? Read on! 

One freezer at -80°C can consume as much energy as an entire average household – and you can save up to 40% (!) of the energy by chilling it up to -70°C. Many labs in academia and the industry have already chilled up their freezers, so there’s a great deal of scientific evidence that most samples are just fine at -70°C. Increasing the temperature of your ultra-low temperature (ULT) freezers also extends equipment lifetime, and your freezers will have more stable temperatures. This translates into less frequent freezer alarms and, most importantly, much fewer night-time trips to the lab to check if a freezer is compromised and needs sample evacuation! 

Still not comfortable? Find more information about chilling up your -80°C freezer here: www.mygreenlab.org/-70-is-the-new--80.html 

 Another point-giving action within the ‘Temperature Tuning’ category is to move samples from colder storage temperature to warmer storage temperatures. Remember that the colder you store your samples the more energy goes into your lab work. That’s why one of the top green cold storage habits is to store your samples at the right temperature; don’t go for the lowest temperature just because you can! It’ll cost you less energy to open a fridge than a freezer, and in terms of environmental impact and costs, it’s much better to get an extra -20°C freezer than an extra ULT freezer! 

Retirements & Upgrades

Another way to earn points in the Freezer Challenge is to retire old fridges and freezers or to replace them with more energy-efficient units. The production, transportation and disposal of appliances leave a significant environmental footprint behind, so it’s not always advisable to replace well-functioning energy-inefficient equipment with new and energy-efficient units. It depends on the age and the condition of your current equipment! But if you’re up for a decluttering challenge, maybe you can discard enough old samples to retire your most energy-inefficient fridge or freezer?

Should you retire any piece of lab equipment, try to avoid trashing it. Perhaps another lab or a local high school would like to adopt it? Alternatively, you can donate it to scientists in 3rd world countries via www.seedinglabs.org. Talent is everywhere, resources are not!

Cutting-Edge Practices

If you want to take your sustainable cold storage to the next level (and potentially make it all the way to Nature), here are three things you can do: 

Firstly, you can earn points by sharing cold storage units with other labs. Maybe one of your -20°C or ULT freezers is half empty ( … or half full) and could be shared with another lab? Maybe you can even unplug or retire a freezer by merging some of your reagents and samples with those of another lab? Secondly, you can earn points by barcoding all samples in a fridge or a freezer as a means to keep track of the contents. Lastly, you will earn points if you start storing samples, reagents or kits which used to be at 4°C (or below) at room temperature. Sometimes we throw kits in the freezer simply because it’s nice to have them stored together. Other times, it’s just one reagent of a kit that should be kept in the fridge – the rest can be kept at room temperature. So take a careful read at the manufacturers’ instructions and look up the advised storage temperature for your samples! And if you are feeling adventurous, the third way to earn points is to test if certain samples or reagents can be kept at room temperature instead of 4°C or below.

Here’s what to do

Now that you know the essentials of the Freezer Challenge – and how simple it is! – it’s time to open a new tab and register your lab at https://www.freezerchallenge.org/ –  and remember to spread the word!