Plastic vs. Glass vs. Silicone Food Containers: Which Is Best?

If you're replacing food containers, the choices can get surprisingly complicated.

Glass is often praised for food storage.

Plastic is lightweight and inexpensive.

Silicone is flexible, hard to break and increasingly common in kitchens.

So which one is actually best?

After spending years developing a reusable food container, my answer is probably less dramatic than you expect: there isn't one material that's best for every situation.

Glass vs. plastic vs. silicone at a glance

Is glass the best material for food storage?

Glass has a lot going for it.

It's rigid, easy to see through when clear and excellent for storing food in the refrigerator.

If I'm putting something into the refrigerator at home and I don't need to carry it anywhere, glass can make a lot of sense.

But glass also has an obvious downside:

It's heavy, rigid and breakable.

Those qualities aren't necessarily a problem in your refrigerator. They become much more noticeable when you're trying to put a container into a purse, work bag, backpack or car and carry it around before you even have food to put inside.

Glass may be your best choice if:

• Most of your food storage happens at home.

• You prefer a rigid container.

• You want to easily see the food inside.

• Weight and breakability aren't major concerns for you.

What are the advantages of plastic food containers?

Plastic became popular for food storage for very practical reasons.

It can be lightweight. It's inexpensive. It doesn't shatter like glass. And manufacturers can create it in an enormous variety of shapes and forms.

It's also important not to lump every plastic food container into one category.

There are many different plastics with different formulations and intended uses.

In the United States, the FDA evaluates food-contact substances based on their specific intended uses and the amount of a substance expected to migrate into food under those conditions.

Source: U.S. Food & Drug Administration, regulation of food-contact substances.

Plastic may be your best choice if:

• Keeping the upfront cost low is your biggest priority.

• You need an extremely lightweight container.

• You need a particular shape or specialized design.

• You're using the container according to its intended food-contact and temperature instructions.

Where does silicone fit?

Silicone fills a very different gap.

It can be flexible without being fragile.

That means designers can create food containers that bend, roll, fold or collapse in ways that simply aren't possible with rigid glass.

And that flexibility is exactly what attracted me to it when I was developing BYOB.

The whole point of BYOB was to create a restaurant-leftovers container that you could carry before you needed a container. For that problem, glass wasn't the right material.

Silicone may be your best choice if:

• You want something flexible and hard to break.

• Portability matters.

• You want to reduce your use of conventional plastic food-storage products.

• A collapsible design would make the container easier to carry or store.

• You're willing to pay more upfront for a product intended for repeated use.

Which material is safest for food storage?

This is the question everyone wants to turn into a ranking.

Glass first. Silicone second. Plastic last.

Or some other version of that list.

I don't think that's the most accurate way to look at it.

A food-contact product also needs to be made from appropriate materials, manufactured properly and used under the conditions it was designed to handle.

That's true whether the container is made from plastic, silicone or glass.

Instead of looking for one material to declare universally "safe," I would look at the specific product and how you're planning to use it.

What about heating food?

This is one area where reading the product instructions really matters.

Some glass food containers are designed to move between refrigerator, microwave and oven. Others have important temperature limitations.

Some plastics are designed for microwave use. Others aren't.

Many silicone food containers are designed for relatively broad temperature ranges, but that still doesn't mean every silicone product belongs in every oven or microwave.

Don't choose your heating method based only on the material category. Check the actual container.

Use the manufacturer's stated temperature limits and instructions for the lid and every component of the product.

What about microplastics?

Concern about microplastics is one reason many people are reducing their use of plastic around food.

Plastic pollution can break down into microplastics and nanoplastics in the environment.

But when we're talking specifically about human health and food, it's important to be precise.

The FDA currently says that available scientific evidence does not demonstrate that the levels of microplastics and nanoplastics detected in foods pose a risk to human health. It also says significant research gaps remain.

FDA also says there currently isn't sufficient scientific evidence to show that microplastics and nanoplastics from plastic food packaging migrate into foods and beverages. Research in this area is continuing.

Source: U.S. Food & Drug Administration, Microplastics and Nanoplastics in Foods.

Which food container is best for meal prep?

If you're doing a week's worth of meal prep at home, glass may be fantastic.

You can stack the containers in the refrigerator, see what's inside and you're probably not carrying all five meals around with you at once.

Plastic can also be practical if weight, cost and having a large number of containers matter most.

Silicone becomes especially interesting when the container also needs to leave the house, fit into limited space or collapse after the food is gone.

Which food container is best for restaurant leftovers?

This is where my answer becomes much less neutral.

Not because glass suddenly becomes a bad material.

Because restaurant leftovers create a different problem.

You have to carry the empty container before you know whether you're going to need it.

A large rigid glass container takes up the same amount of room in your bag when it's empty as it does when it's full.

A rigid plastic container is lighter, but it still takes up space.

A collapsible silicone container can solve that particular problem in a way the other two materials don't.

Which material is best for kids, travel and on-the-go food?

Once a food container starts traveling, weight and breakability become much more important.

That's one reason plastic remains popular for lunchboxes and travel.

Silicone offers another option when you want something lightweight and flexible without using a conventional plastic container.

And if the silicone container collapses, you also get the benefit of carrying less bulk once the food is gone.

What about environmental impact?

This comparison gets complicated quickly too.

A reusable product has to be manufactured, transported and eventually disposed of no matter which material you choose.

Glass isn't automatically environmentally perfect. Silicone isn't biodegradable. And plastic varies enormously in composition, lifespan and recyclability.

So I focus on something much more practical:

Will I use this container again and again instead of repeatedly reaching for something disposable?

Durability and actual use matter. A reusable container doesn't accomplish much sitting untouched in a cabinet.

My recommendation: choose based on the job

I don't think your kitchen needs to choose sides.

You can own glass and silicone.

You can have a plastic container that works perfectly well for a specific purpose.

Instead of asking, "Which material should replace everything else?" I would ask:

Frequently asked questions about glass, plastic and silicone food containers

Is glass safer than plastic for food storage?

Glass has advantages as a food-storage material, but it's overly simplistic to say every glass container is "safe" and every plastic container is "unsafe." Food-contact suitability depends on the specific product, its components and how it is intended to be used.

Is silicone better than glass for food storage?

It depends on the use. Glass is excellent for rigid at-home storage. Silicone can be more convenient when flexibility, reduced weight, break resistance or collapsibility are priorities.

Is silicone better than plastic?

Silicone can be a useful alternative for people trying to reduce their reliance on conventional plastic food-storage products, but neither material can be judged by its name alone. Look at food-contact suitability, testing, intended use and temperature instructions.

Which material is least likely to break?

Flexible silicone won't shatter like glass. Many plastic containers are also resistant to breaking, although they can crack, scratch or wear with use depending on the material and design.

Which food container is best for taking to restaurants?

Portability matters more for restaurant use because you have to carry the empty container before you know whether you'll have leftovers. A lightweight collapsible silicone container can be particularly useful because it takes up less space when you're not using it.

Should I throw away all of my plastic food containers?

Not necessarily. If a food container is in good condition, intended for food contact and being used according to its instructions, replacing everything at once may not be necessary. You can transition materials over time based on your own priorities and how you use each container.

Bring Your Own Box,
Rachel