What type of lunch box?

When it comes to selecting the ideal lunch box, there is no one-size-fits-all choice; it all depends on your specific requirements. In this section, I've summarised the most common lunch box materials in a handy chart, followed by more detailed information below.

As a PhD in Chemistry who also studied Material Science, I absolutely love to geek out on this stuff! I've researched using independent resources to give you a well rounded perspective.  You might be wondering why price point is not included here, I’ve not reviewed it because you can buy very cheap and very expensive versions of all the materials and quality of products varies significantly. If you have any questions, or want to know about other materials, please contact us here.

Stainless Steel

Stainless steel is my go-to material when possible, so much so I created this lunch box company! This material is a great option for almost all situations unless you want to microwave your food. Along with glass it is one of the least environmentally harmful materials. It is infinitely recyclable without losing it's properties. You likely own a lot of stainless steel products already like cookware and cutlery and it has stood the test of time, it's been around for over 100 years!

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What is stainless steel and how is it made?

Many stainless steel products are made from recycled material but originally all components were raw mined materials. Stainless steel is a mixture (called an alloy) of a few different elements, the largest component is iron and other elements such as nickel and chromium are added to increase strength and resistance to corrosion. The most common type of stainless steel used in lunch boxes is 304 (18/8) stainless steel, containing 18 percent chromium and 8 percent nickel. Stainless steel is made by heating the metals or metal scraps together in an electric furnace followed by a shaping process.

Pros of stainless steel

  • Stainless steel is incredible durable. The metals that make stainless steel make it super tough. The chromium also gives stainless steel a protective layer, making it rust resistant and corrosion resistant. Scratches and scuffs may appear over time but they have no impact on the properties of the material.
  • It is non-toxic. Many materials, such as plastic, can leach chemicals into your food, with stainless steel this is not an issue.
  • It is not fragile, your child can accidently drop it and it won't break into dangerous shards.
  • It usually comes without any artificial colourings added, they are metal containers and they look like metal
  • Easy to clean. It can go in the dishwasher! Top rack or bottom rack!
  • It is 100% recyclable with no reductions in the properties of the metal, in fact many of the stainless steel items you own will have a large proportion of recycled steel. There is little impact on landfills.

Cons of stainless steel

  • The biggest disadvantage is that it cannot be microwaved (there are a few products out there that say they are microwavable stainless steel but I wouldn't recommend microwaving metal. If there are any non-round edges (inc. dents/scratches) this will increase the risk of ignition and microwaves do not penetrate steel so it would take a long time to heat up your food. 
  • It is not transparent so you can’t see what’s inside.


Silicone has gained huge popularity in recent times. It is a practical material that can be microwaved, frozen and is really durable. The main downside is that, despite a lot of green marketing by companies, it's not as environmentally friendly as other materials. As a porous material, it also absorbs odours easily. Many argue that it is actually a type of plastic. However, it is far more durable than other plastics and does not leach as many micro particles.

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What is silicone and how is it made?

Silicone is made from silica which is a raw mined material and a carbon source (e.g. coal). Silica is abundantly available in the form of quartz/sand. To make silicone there are a few steps. First, the silica (quartz) is heated with the carbon source in an industrial furnace to make the element Silicon. This is then reacted with some fossil fuel derived hydrocarbons to make siloxane monomers which are then bonded to make the final polymer that is silicone.

Pros of silicone

  • It is a very practical material, you can heat it in the microwave or the oven, you can put it in the fridge or freezer. It can withstand really high temperatures and cold temperatures without breakdown or becoming damaged.
  • It is incredibly durable and so hard to break.
  • It’s easy to clean, you can put it in the dishwasher. 
  • Does not break down into micro plastics so is not as damaging to wildlife as plastic.
  • It does not leach as many micro particles into your food so you’re ingesting less micro plastics.

Cons of silicone

  • It absorbs odours easily.
  • While it is better than plastic, it does require some fossil fuel derived materials to produce.
  • Recycling is difficult and when recycled silicone does lose some structural integrity.
  • It takes a long time to break down but does not produce micro particles so is not as damaging to wildlife as plastic.
  • It is not as widely researched yet as other materials.


Plastic gets such a bad rap and although it has many downsides it does have uses in society and you can buy it very cheaply. Almost all plastics used for lunch boxes will be free from the big nasties you hear of like BPA and phthalates these days, but it’s always worth checking this. Plastic is not my choice for an everyday lunch box. My opinion when it comes to plastic is to reduce use when possible especially when there’s a practical alternative available.

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What is plastic and how is it made?

There are a large number of materials that can be defined as plastic but for the purpose of this review I am considering Low-density polyethylene (LDPE), High-density polyethylene (HDPE), Polyethylene terephthalate (PET), and Polypropylene (PP). These plastics are made from materials derived from fossil fuels. Natural gas, oil or coals are refined into chemicals called ethane and propane; these are then heated to make ethylene and propylene which are turned into polymers that make plastics.

Pros of plastic

  • You can take it to sporting events and festivals. Often the only material you’re allowed to bring to these events is transparent plastic, I have a couple of plastic containers for this purpose.
  • It can be transparent so you can see the contents inside.
  • Plastic can be very lightweight, makes it easier to move around.

Cons of plastic

  • Plastics cannot be put in the oven and the material can become brittle in the freezer.
  • It absorbs the smells and tastes of food more easily than other materials.
  • One of the biggest downsides of plastics is the environmental impact; It is a non-biodegradable material, it causes pollution and harms wildlife. Only 9% of plastics have ever been recycled.
  • Plastics leach more microparticles into your food especially if your food is acidic (for example if it contains lemon juice or vinegar).
  • You can technically microwave some plastics, but it’s not recommended. Many plastics will leach a lot more chemicals if microwaved. 
  • They are not always dishwasher safe, check before dishwashing. Use caution even when products are marked dishwasher safe as some plastics can release significant microparticles when heated (like in the dishwasher).


If I wasn’t such a butter fingers and didn’t mind the weight of glass this would be a great material for lunch boxes. I often use glass to store things at home and love it! It can go in the microwave, oven, fridge (sometimes it can go in the freezer but you need to check, not something I ever do!). As I mentioned before, the production of no material is 100% environmentally friendly but glass is one of the better materials.

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What is glass and how is it made?

Glass is made from sand, soda ash and limestone. These are all raw materials that are abundantly available. To make glass they’re all heated together at very high temperatures to turn them into a liquid, the molten material is shaped and tempered to desired shape.

Pros of glass

  • Glass is transparent which is helpful to see the contents of your container.
  • It can go in the microwave, oven and fridge. 
  • It is an environmentally friendly material, it is 100% recyclable without losing properties and doesn’t need a carbon raw material to make it (as said above no material is perfect, glass requires high temps to make and releases some greenhouse gases).

Cons of glass

  • Glass is easily breakable, shards can be very sharp and dangerous. It is not a good material for children.
  • It is heavy, which can make transportation difficult.
  • It is not always freezer-friendly.
  • As mentioned before, no material is 100% environmentally friendly. Glass requires high temps to melt and some greenhouse gases are released but it is certainly one of the better materials.