Most people choose containers based on what’s clean, what’s available, or what was cheapest at the time. Very few think about what those materials do once food touches them.

The decision seems trivial until you realise that microplastics and chemical residues are now turning up in human blood, organs, and brain tissue. The container you grab out of the cupboard is one of the few variables you fully control.

Plastic: convenient, but not neutral

Plastic food containers are light, cheap, and everywhere. They are also chemically complex.

Additives like plasticizers, stabilisers, and colorants are used to achieve flexibility, durability, and colour. Some are well studied. Many are not.

Heat accelerates everything. A container that is stable at room temperature can behave differently in a microwave, dishwasher, or on a counter when hot food is poured in. Scratches and clouding are visible signs of wear, but shedding and migration start long before the plastic looks damaged.

Over time, that means more microplastic particles and more chemical residues moving into food.

“BPA-free” addresses one chemical family. It does not make the container inert.

Glass: chemically stable, physically fragile

Glass doesn’t need plasticizers or stabilisers to stay rigid. It doesn’t rely on a polymer matrix that breaks into microplastics. Under normal kitchen conditions, it doesn’t react with food or release chemical additives into it.

That’s why it’s used in labs when the goal is to avoid contamination.

The trade-off is practical, not chemical. Glass is heavier. It can break. It takes up more space in a bag or a lunchbox. But from the perspective of what touches your food, it’s close to neutral.

Stainless steel: durable and predictable

Food-grade stainless steel is an alloy. It includes chromium and often nickel to resist corrosion. When you hear about “stainless steel grades”, that’s what’s being described - how resistant the material is to pitting, rust, and reaction with different foods.

High-quality stainless steel is hard-wearing, doesn’t chip, and won’t shed microplastic particles because it isn’t plastic.

It can interact with very acidic or salty foods over long exposure, but in normal kitchen use it is considered one of the most stable options available for cookware and containers.

The material hierarchy

If you think in terms of what’s in direct contact with your food the most often, a rough hierarchy emerges:

• Glass and high-quality stainless steel at the top. Stable, durable, and as close to chemically quiet as you can reasonably get in a home kitchen.

• Natural materials like solid wood for short-contact items such as chopping boards and utensils.

• Plastic as a last resort, and never as the default for hot food or repeated heating.

You can’t avoid every exposure from packaging, air, and water. But you can decide that in your own kitchen, the surfaces touching your food aren’t a source you’re adding to.

What this looks like in practice

In practical terms, that means:

• Using glass or stainless steel for leftovers, especially if they’re still warm.

• Choosing stainless steel over non-stick or plastic-coated options where possible.

• Keeping plastic for cold, dry storage when you have no alternative—and phasing it out over time.

At Grain & Ridge, every product is designed around that hierarchy.

Natural, non-toxic materials first. No synthetic coatings, no plastics marketed as something they’re not, and nothing in contact with your food that we wouldn’t put in contact with ours.

You can shop the collection here.