Food storage without plastic: cling film, bags, wraps and freezing

Cling film is the kitchen’s most passive-aggressive product: it clings to itself, it won’t tear straight, and depending on which roll you bought, it may be feeding plasticiser into your cheddar. Food storage is also where most of us could cut plastic fastest and cheapest, because the replacements (jars, plates and tins) are already sitting in the cupboard.

This guide covers what you put leftovers in, wrap things with and freeze things in. It doesn’t cover heating. For what happens when plastic meets the microwave, read our guide to microwaving plastic. For cutting boards, kettles and pans, see our ranked kitchen swaps.

Cling film: there are two kinds, and they behave differently

“Cling film” isn’t one material. It’s mostly two:

• PVC (polyvinyl chloride, resin code 3). Rigid PVC is what drainpipes are made of. To make it soft and clingy, manufacturers add plasticisers. The workhorse in cling film has long been DEHA, di(2-ethylhexyl) adipate, which is not a phthalate but is chemically close to one.
• LDPE (low-density polyethylene, resin code 4). It clings less, so makers often add a tackifier such as polyisobutylene. It doesn’t need a plasticiser in the way PVC does.

PVC film is common in shops, delis and catering because it clings hard and stretches. Rolls sold for home use vary by brand and country. If the box doesn’t name the polymer, you can’t tell which you have. For a rundown of the resin codes, see our guide to plastic types 1 to 7.

Fat pulls plasticiser out of PVC

DEHA is oily, so it moves into fat. That’s been measured repeatedly for nearly 40 years.

• In a UK survey of 83 shop foods wrapped in PVC film, DEHA levels were 27.8 to 135 mg/kg in cheese, 11 to 212 mg/kg in baked goods and sandwiches, and under 2 mg/kg in fruit and vegetables. The more fat touching the film, the more DEHA: the mayonnaise in a sandwich or the fat on a cut of meat. Grilling or frying the meat afterwards didn’t significantly reduce it.
• The same team tested home-style use. Migration rose with contact time and temperature, and was highest for cheese, cooked meats, cakes and food cooked in the microwave under film. Unfilled sandwiches, fruit and veg (except avocado) picked up much less. So did covering a container where the film barely touched the food.
• Danish researchers wrapped cheese in a “low migration” PVC film. After two hours in the fridge the cheese held 45 mg/kg DEHA, and after 10 days 150 mg/kg. The authors warned that people who eat a lot of film-wrapped cheese could get close to or above the tolerable daily intake then in force, 0.3 mg per kg of body weight.
• A later Danish enforcement campaign found that 46 of 49 PVC films exceeded the legal migration limit in lab tests with olive oil, the official stand-in for fatty food.
• More recently, fish fillets wrapped in PVC film at 2°C picked up 92 to 118 mg/kg DEHA at equilibrium, and the trout exceeded the EU limit. Fish skin cut migration more than twofold.

For scale, the EU’s specific migration limit for DEHA in food is 18 mg/kg. Several of the results above exceed it many times over.

Does it get into people? Yes. In a 2019 German study, six volunteers ate food wrapped in DEHA-containing PVC film, and DEHA breakdown products turned up in every urine sample afterwards. That shows exposure, not harm. DEHA is a weak actor next to the worst phthalates, and nobody has shown that cling film on cheese makes people ill. But the cheese wasn’t asking for an extra additive either.

One caveat in the industry’s favour: most of these studies are 15 to 40 years old, and formulations and enforcement have moved on. Nobody we found has re-run a large retail survey recently. That’s a gap, not a clean bill of health.

PVC isn’t the only soft wrap with additives. Some PVC and PVDC wraps also contain epoxidised soybean oil as a plasticiser and stabiliser. It didn’t migrate into water or acidic simulants, but did migrate into oily ones. Same story: fat is the solvent.

LDPE film is better, not clean

Polyethylene film doesn’t rely on DEHA, but its tackifier moves too. In a UK study, polyisobutylene from polyethylene film reached 8 to 10 mg/kg in cheese, 1 to 5 mg/kg in cake and under 1 to 4 mg/kg in sandwiches. When the film only met steam while food was reheated, migration was under 0.01 mg/kg. Polyisobutylene is a fairly inert polymer, so this is much less worrying than DEHA. It still shows the rule: anything soft and sticky in plastic film is there to move.

What to do with the roll you already have: if it says PVC, or says it’s unsuitable for fatty foods, keep it away from cheese, meat, pastry, oily food and anything hot. Better still, use it up on things that don’t touch the film, then don’t rebuy it. A plate on a bowl does the same job for free.

Zip bags and freezer bags

Zip-top bags are usually polyethylene, sometimes with a polypropylene zip. They don’t need plasticisers, so the chemical worry is smaller than with PVC film. The issue is particles.

The best evidence comes from a study of containers and pouches. Storing food simulants for over six months in the fridge or at room temperature released millions to billions of micro- and nanoplastic particles, and the polyethylene pouch released more than the polypropylene containers. That was a lab test with water and dilute acid, not real food, and particle counting methods are still argued over. Opening plastic packaging also generates particles. Cutting, tearing and twisting packaging open produced about 0.46 to 250 microplastics per centimetre in one study. That study tested packaging in general, not zip bags.

We found no study that measured what freezing, thawing and refreezing does to a polyethylene bag. So the honest position is that bags are a low-to-moderate concern, mostly about particles, worst with long storage and repeated use. Reusing a bag beats binning it after one use. Washing and reusing the same bag for years means the plastic wears in contact with your food. That’s a reason to retire bags as they cloud and crease rather than keep them forever.

Plastic lids on glass containers

The most common “plastic-free” container is a glass box with a plastic snap-on lid and a rubbery seal. It’s a big improvement on an all-plastic box, but it isn’t plastic-free.

The lid matters less than the box, because in normal fridge use it barely touches the food. The risks come when it does: when soup is filled to the brim, when the box is stored on its side, when food sits against it for days, or when the whole thing is microwaved or run through a hot dishwasher. Heat and fat are the accelerants here, just as with cling film. We cover those in our microwaving guide.

That’s also how our product standard treats them. A glass or steel container with a plastic lid can be listed only as “plastic-minimal”, and only if the lid doesn’t touch food in normal use. If it does, it’s rejected.

Practical rules:

• Leave a gap between food and lid. Never microwave with the lid on; use a plate.
• Hand-wash lids or put them on the top rack. Replace lids that warp, crack or turn chalky.
• Check the seal. A silicone gasket is still silicone (see below), and removable gaskets need to come out for cleaning or they grow mould underneath.
• Glass jars with metal screw lids are the cheapest upgrade. Most metal lids have a plastic or rubber lining, but it’s a small surface that rarely touches food in a jar that isn’t brim-full.

Beeswax wraps: what’s in them, and do they stay clean?

Beeswax wraps are cotton fabric coated in wax, usually beeswax plus tree resin and a plant oil to make it tacky. They’re a real plastic-free swap for covering bowls and wrapping bread, cheese, halved vegetables and sandwiches. But “natural” isn’t the same as “clean”, and the evidence on them is thinner than their fans assume.

Hygiene

You can’t wash a wax wrap in hot water, because the wax melts. Makers say to wash them in cool water with a little soap, and that limits what you can safely put in them.

• In a small test, new wraps passed a standard surface-cleanliness swab. Wraps smeared with avocado, then washed in cold water as the instructions said, failed the same test, meaning food residue remained. The authors recommended labelling wraps for specific food types. This was a small student study using a residue swab (ATP), which measures organic residue rather than bacteria, so it’s a warning sign rather than proof.
• A lab study of one commercial wrap found it significantly reduced counts of several kinds of bacteria, but showed no effect on fungi or viruses. That’s one product in a lab, not a guarantee that a used wrap stays clean.

The cautious rule follows from the cold-water limit: don’t use wax wraps for raw meat or fish, and keep separate wraps for strong-smelling or messy foods. Use a lidded glass or steel container instead.

What else is in the wax

Beeswax comes from hives, and hives sit in a polluted world. Beekeepers also treat hives with mite-killing chemicals that are fat-loving, so they accumulate in wax.

• Commercial Swiss beeswax collected in 2019 held 7 to 14 pesticides per sample, led by the hive treatments coumaphos (mean 401 µg/kg) and tau-fluvalinate (mean 236 µg/kg).
• A 2024 study that tested beeswax specifically because it is used to coat and wrap food found that every wax sample carried at least one contaminant, and the phthalate DEHP was present in all the beeswax samples. The authors note there are no EU maximum limits for contaminants in these waxes.
• Fraud is a problem too. EU Joint Research Centre scientists found adulteration, mostly with paraffin, in 27% of commercial beeswax products they tested, such as candles and blocks, compared with 12.5% of honeycomb-type samples. Paraffin is a petroleum wax.
• The first study we know of on finished wraps comes from Germany’s federal risk assessment institute and the University of Hohenheim. It found chlorinated paraffins, industrial flame retardants and plasticisers, in all 26 wraps tested. New wraps held 0.2 to 15 µg per square decimetre. Two used wraps held far more, 20 and 260, suggesting wraps soak up these chemicals from contaminated indoor environments over time. The transfer into food was calculated, not measured, but the authors conclude wraps can add to exposure.

What we didn’t find: any peer-reviewed test of PFAS in beeswax wraps. If someone has done one, we’d like to see it. (For why PFAS matter, see our PFAS explainer.)

One more thing: the tackiness usually comes from pine resin (colophony), a well-known skin allergen. There’s a published case of a woman who developed recurrent face and eyelid eczema after starting to sell beeswax wraps. That’s one case report, but if you react to plasters or adhesives, check the ingredients.

Our take: wax wraps are still a reasonable swap for bread, cheese, fruit and veg, used at room temperature or in the fridge. They aren’t a contaminant-free material. Buy ones that list every ingredient, replace them when they stop sticking, and don’t keep them for years. Don’t put them near heat, and don’t use them for raw meat or fish.

Freezing in glass without cracking it

Glass is the best freezer material most people already own. It fails in two predictable ways.

1. The food expands. Water-based food expands as it freezes, and if it has nowhere to go it breaks the jar. The US National Center for Home Food Preservation warns that expanding liquid can break jars at the neck. Its headspace table for liquid packs asks for ½ inch (about 1.3 cm) in a wide-mouth pint and 1 inch in a wide-mouth quart. Narrow-mouth jars need ¾ inch for a pint and 1½ inches (about 4 cm) for a quart.

2. Thermal shock. Glass cracks when one part expands or contracts faster than another. The same centre notes that “regular glass jars break easily at freezer temperatures”. It recommends wide-mouth jars made for both canning and freezing, which are tempered, and straight-sided shapes so frozen food slides out. Consumer Reports’ advice from its glass bakeware tests applies here too: don’t move dishes straight from freezer to oven or back.

What to look for:

• Straight sides and a wide mouth. Avoid jars with a “shoulder” for liquids. The neck is where they crack.
• Glass sold as freezer-safe. In Consumer Reports’ deliberately harsh test, dishes filled with hot sand were moved from the oven onto a wet granite counter. Soda-lime glass dishes broke 10 times out of 10 after 450°F, while European borosilicate dishes survived at that temperature, though most broke at 500°F. Manufacturers counter that their soda-lime glass is less likely to break when dropped or bumped. Neither material is shatterproof. Either will do for the freezer if you avoid sudden temperature jumps.
• Cool food first, thaw gently. Let hot food cool before it goes into a jar destined for the freezer. Thaw jars in the fridge, not under hot water.
• Discard chipped or scratched glass. Consumer Reports advises binning dishes with chips, cracks or scratches.

If you freeze a lot of soup and stock, stainless steel tins avoid the cracking problem entirely, at the cost of not seeing what’s inside.

Stainless steel containers

Stainless steel is tough, light, freezer-proof and doesn’t shed plastic. Most food-grade stainless is grade 304 (also sold as 18/8 or 18/10) or 316. Those are the grades most used in the food industry, and both contain nickel and chromium.

Steel isn’t completely inert either. In a study simmering tomato sauce for hours, nickel rose up to 26-fold and chromium up to 7-fold after six hours, depending on the grade. New steel leached most, and leaching fell over repeated uses, levelling off after about six cooking cycles. That was hours of hot, acidic cooking. Cold storage is a much milder test, but we found no study that measured it. If you have a nickel allergy, ask your doctor about storing acidic food in steel.

What to look for:

• A named grade (304/18-8 or 316). “Surgical steel” or “food grade” without a number is a red flag.
• No plastic coating or liner inside the container. Some “steel” lunch boxes are lined.
• The lid. Many steel containers have plastic or silicone lids, which puts them in the same “plastic-minimal” category as glass with a plastic lid. All-steel lids with a clip exist, but they’re rarely airtight.
• Season it before acidic food. Since new steel leaches most, give a new tin a few washes and some non-acidic uses before you store tomato sauce in it for days.

Silicone bags and lids

Silicone bags are sold as the reusable answer to zip bags. Silicone is a synthetic polymer, not a conventional plastic, and it isn’t inert. We cover it in depth in our silicone guide. For storage, the short version:

• Cold, watery food is the easy case. An FDA study found no siloxanes in milk or infant formula after six hours in direct contact with silicone at 40°C.
• Fatty food is the hard case, even without an oven. Silicone moulds used to make chocolate at no more than 45°C released 21.5 mg/kg of siloxanes into it by the third use.

So a silicone bag is a reasonable way to freeze berries or stock, and a worse way to keep cheese or oily leftovers. By our standard, anything with silicone touching food is never “plastic-free”.

A transition plan that won’t cost much

The most expensive way to go plastic-free is to throw everything out at once and buy a matching set of glass boxes. It also wastes the plastic you already paid for. Here’s a cheaper order, roughly by evidence and value:

1. Stop putting cling film on fatty food today. Free, and it targets the best-documented problem in this article: plasticiser moving into cheese, meat and pastry. Use a plate over a bowl, an upturned bowl over a plate, or a lidded container.
2. Never heat food in plastic storage. Free. Decant into a ceramic bowl or glass dish first. See our microwaving guide.
3. Keep your jars. Jam, pickle, passata and nut-butter jars are free glass storage. Wide-mouth, straight-sided ones are the best for freezing, as long as you leave headspace.
4. Retire plastic as it fails. When a container cracks, clouds, stains or warps, replace it with glass or steel rather than more plastic. Do the same with zip bags as they wear.
5. Buy a few freezer-safe pieces where they earn their keep. If you batch-cook, a handful of tempered or freezer-safe jars and a couple of steel tins cover most needs. Buy the size you actually use, not a 24-piece set.
6. Use wax wraps for what they’re good at. Bread, cheese, halved fruit and veg, and covering bowls. Not raw meat or fish, not hot food.
7. Keep one roll of LDPE film for emergencies, or none. If you still want film for the odd job, choose a roll that names polyethylene, and use it where it won’t touch fatty food.

Where the evidence is weak, we’ve said so. Nobody has run a big modern survey of DEHA in shop food, nobody has measured what freezing does to a plastic bag, and wax wraps have barely been studied. The strongest, most repeated finding is the oldest one: soft PVC film plus fatty food means plasticiser in your dinner. Start there.

For how we judge products, see our standards. More in our kitchen section.