Why Do Labs Use So Much Single-Use Plastic?  

If you are in the business of reducing plastic waste, life science laboratories are your worst nightmare. So much of the plastic in labs is used once and then thrown out. Most of it can’t even be recycled! It has been estimated that, globally, life science labs produced as much as 5.5 million tonnes of plastic waste in 2014 alone! That is around 83% of all the plastic that was recycled in 2012.

In this post, we’ll be looking at some of the reasons why plastic waste is such a problem in labs, and what we can do to change things. This post is based on a series of interviews that Grain-4-Lab has conducted with scientists from various disciplines.

The Problem of Sterility and Contamination

One of the main reasons why most plastics in life science labs can’t be reused is that they often need to be completely sterile. This means there can’t be any microbes living on the surface of the plastic that might interfere with the experiment that is being carried out.

Think of an experiment that requires you to grow a culture of bacteria in a petri dish. If there is even a tiny amount of different, unwanted bacterial cells in the petri dish at the beginning of the experiment, then they will grow in the agar along with the bacteria you are trying to culture. If all the petri dishes in the experiment have this problem, then you could be looking at losing days of work!

If you want to reuse a piece of plastic in a life science lab, you will often have to sterilise it using a machine called an autoclave. The way this works is that you put the material in a chamber, which is then pressurised to heat it up. The heat is what sterilises the material.

One issue with using bioplastics like PLA in a life science lab is that many of them have relatively low thermal resistance. That means that you have to figure out which chemicals you can add to the plastic to make it stand up to the temperatures in an autoclave without warping!

It is not just microbes that are an issue. In a chemistry lab, for example, the problem with reuse might be the trace amounts of chemicals left over from a previous experiment. If you need to test the chemical composition of a sample, leftover chemicals could ruin your experiment!

Other Considerations

As well as sterility, there are a few other reasons why labs need to use very specific types of plastic. One is transparency. This can be necessary if an experiment requires you to be able to observe what is happening inside a container. This adds an extra challenge for people trying to design materials to replace lab plastics.

Another major consideration is biocompatibility. This means that the material won’t interfere with any organisms in contact with it. Going back to the example of the petri dish, you will certainly not be able to conduct cell cultures in a dish which kills microorganisms instantly!
Price is another big one. Scientists often have a tight budget that they need to stick to, particularly towards the start of their career. Mass-produced fossil fuel plastics are almost always the cheapest option, which makes it hard to convince people to change their purchasing.

Why Can’t We Just Go Back to Glass?

Some people think this is the way to go! There are, however, a few issues with this solution. One problem is that if you are working with dangerous chemicals or infectious diseases, there is a safety issue with using a breakable container.

In the case of infectious diseases, you want your lab to be completely free of ‘sharps’. Anything that can break your skin is considered a sharp in a lab setting. That means that you might need special permissions to use glassware, since if it breaks it becomes a ‘sharp’. It is often easier, then, from a safety perspective to just use single-use plastics for everything.

Another reason why glass might be problematic is the chemicals that are used to clean them for reuse. If you need your glassware to be completely sterile, you may need to soak it in harsh chemicals which can then travel through the drains and end up entering the environment. On top of that, there is the carbon footprint of cleaning the glass to consider. Autoclaves can use quite a lot of energy!

There are still people who argue, however, that glass is the way forward. After all, scientific research was carried out effectively for decades before we started using plastics for everything. You might need to be a bit more careful about dropping samples, true, but you could make the argument that it is worth the risk considering the damage plastics are doing to the environment.

What Can Be Done About It?

There are a few different ways to reduce the amount of petroleum-based plastics being used in labs. Below, we will go through a few of the main options available. You are probably already familiar with the ‘3 Rs’ – reduce, reuse and recycle. Did you know, however, that they are arranged in order of importance? Reducing is better than reusing, and reusing is better than recycling! All three options, however, are better than landfill or incineration.

reduce

At the top of the ‘waste hierarchy’ is reduction. There is nothing you can do that is more effective for improving waste management. If you can reduce the initial amount of plastic waste being produced, that is less plastic that needs to be reused, recycled, sent to landfill or incinerated.

In a lab setting, there are a few ways to reduce plastic waste. One way is to downsize the plastics you are using. If you are consistently only filling a sample tube to half capacity, for example, you might want to think about buying tubes that are half the size!

Another method is to do an inventory of which plastics are necessary for the experiment, and which are there solely for convenience. By assessing the value of the materials to the science, you can quickly see where the reductions can be made!

Bulk-buying is another great way to reduce plastic, since bulk orders are often wrapped in less packaging overall than the same amount of product bought in several different orders. Less trips in the delivery truck also means lower greenhouse gas emissions. Be careful, however, that you are not buying more than you can use for the sake of it!

reuse

Next up on the waste hierarchy is reusing. As we have already discussed, reusing plastics in life science labs can become quite tricky due to the requirements of sterility and contamination. Certain things like weighing boats and gloves, however, can often be reused!

When it comes to gloves, there is a balance to be struck. Thicker gloves are better for reusing, but they also use more plastic to produce. Only buy thick gloves if you are sure you can reuse them enough to justify the extra plastic needed to make them.

recycle

Right at the bottom of the waste hierarchy is recycling. Don’t let that fool you though, recycling is still a lot better than landfill or incineration. Every bit of plastic that is recycled is a bit of plastic that will not end up in the environment damaging ecosystems.

Recycling also has to deal with the problem of contamination. As you probably know from home recycling, you can’t put plastic with food waste on it in the recycling bin. If recycling plants can’t deal with food waste, then they certainly can’t deal with dangerous chemicals or diseases!

replace

The final option for getting rid of fossil fuel plastics is to simply replace them with a different material like glass or bioplastics. We have already talked a bit about the issues with replacing plastic with glass, so let’s move on to bioplastics.

One big issue with compostable bioplastics is that they often don’t get disposed of correctly, whether that is because people don’t know it can be composted, or they simply don’t have access to a compost bin. Compostable plastics need to be taken to an industrial composting facility and cannot be used in your home compost.

Fortunately, this is not so much of a problem in labs. Labs already segregate their waste perhaps more than any other type of building. Whether it is a biohazard, sharps or radioactive waste, there are plenty of reasons to segregate waste. For this reason, labs are seen as a great candidate for compostable bioplastics.

Summary

Labs are one of the trickiest places to try and reduce plastic waste due to considerations like sterility requirements, budgetary concerns, safety, transparency, biocompatibility and more. In this post, we have gone through a few of the ways to reducing the amount of plastic waste going from the lab to incineration or landfill.

Considering that life science labs alone produce an estimated 5.5 million tonnes of plastic waste per year, it is clear that something needs to be done soon.

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