Ice Bags: Sizes, Film Types and Food Safety Explained

If you sell ice, the bag is doing more work than most people give it credit for. It has to survive being filled at speed, tied off, dropped into a chest freezer, stacked under fifty other bags, frozen solid, and then dragged out by a customer on a hot Saturday afternoon. An ordinary poly bag will not last that cycle. It goes brittle in the cold and splits along the fold, and you lose the sale plus the ice.

This guide covers the two sizes that dominate the Australian market, the difference between the HDPE and LDPE films used to make them, the food safety questions worth asking your supplier, and how to work out what to order. If you already know what you need, the full range of empty ice bags is available in bulk cartons.

Why an ice bag is not just a poly bag

Polyethylene gets stiffer as the temperature drops. That is normal behaviour for the material. The problem is that a film chosen for room temperature performance can lose enough flexibility below zero that it cracks under impact rather than flexing. In a freezer full of hard-edged ice, impacts happen constantly.

Ice bags are made from film selected to stay pliable at sub-zero temperatures. Practically, that means three things for you: the bag does not crack when a customer knocks it against the freezer door, the seal along the bottom holds when the contents settle, and the bag does not leak meltwater across your floor when it comes back out into the warmth. Clear film matters too, because customers buying ice want to see it.

Ice bag sizes in Australia: 3.5kg and 5kg

Two sizes cover the overwhelming majority of Australian ice sales. Both are sold empty, in bulk cartons, and both are sized generously so there is room to fill, fold the top over, and tie off without fighting the bag.

3.5kg ice bags: 305 x 450mm, 25µm HDPE

This is the party bag and the servo bag. It is the size most people picture when they think of a bag of ice from a convenience store freezer. At 305 x 450mm it holds roughly 3.5kg of cubed ice with enough headroom at the top for a twist tie.

The film is 25µm HDPE. High-density polyethylene is stronger per micron than low-density film, which is why a 25µm HDPE bag performs well despite the light gauge. It has a slightly crinkly feel and less stretch. 3.5kg ice bags come in cartons of 2,000, which suits high-volume bagging where cost per bag is the number that matters.

5kg ice bags: 350 x 620mm, 50µm LDPE

The 5kg bag is the workhorse for events, catering, fisheries and anyone selling ice by volume rather than by impulse. At 350 x 620mm it is noticeably longer than the 3.5kg bag, which gives you a proper fold at the top.

The film is 50µm LDPE with a linear low additive. Low-density polyethylene is softer and stretchier than HDPE, and the linear low component adds puncture and tear resistance. That combination is worth having when the contents are sharp-edged ice and the bag is being handled by customers rather than staff. 5kg ice bags come in cartons of 1,000.

One practical note on both sizes: because of how plastic film is manufactured, a variance of plus or minus 3 to 5% in length and width is normal and accepted across the industry. If you are specifying bags for an automated bagging machine, allow for that tolerance.

Shop ice bags and twist ties

HDPE vs LDPE: which film suits your operation

The two sizes use different films, and that is not an accident. Each has a job it does better.

HDPE is denser and stiffer. It gives you tensile strength at a thinner gauge, so a 25µm HDPE bag can outperform a thicker LDPE bag on straight pull strength, and it uses less material per bag, which usually shows up in a lower unit cost. The trade-off is that HDPE has less stretch, so it absorbs sharp impacts less forgivingly.

LDPE is softer, clearer and more elastic. It stretches before it tears, which is exactly what you want when a bag full of ice cubes gets dropped, and a linear low-density component lifts puncture resistance further. The trade-off is that you need more microns to hit the same tensile figure, so the bag costs more per unit.

For most operators the choice is made by size rather than film preference: the 3.5kg bag is HDPE, the 5kg bag is LDPE, and both have been specified for the job. If you also buy general-purpose bags elsewhere in the business, our poly bag range covers the same materials across more sizes and gauges.

Food safety: what applies to bagged ice in Australia

This is the part people skip, and it is the part that costs money if you get it wrong.

Ice is treated as a food

In Australia, ice intended for consumption is regulated as a food. That means the water it is made from, the equipment it touches, and the packaging it sits in all fall under the Food Standards Code, and your operation falls under the food business requirements administered by your state or territory and your local council. It is not a grey area, and a health inspector will treat a bag of retail ice the same way they treat a punnet of berries.

Ask your supplier the right questions

Any packaging in direct contact with food should be made from material suitable for food contact use. Before you commit to a bulk order, ask your supplier three things in writing:

1. Is the film virgin polyethylene, or does it contain recycled content? Recycled content in direct food contact packaging carries different requirements.
2. Can you provide documentation confirming the material is suitable for food contact?
3. Are there any additives, pigments or slip agents in the film that I should be aware of?

QIS ice bags are manufactured from clear polyethylene film specified for freezer use. If your council, auditor or customer requires documentation for your food safety program, contact us before you order and we will get you what the manufacturer can provide. Requirements vary between states and between certification schemes, so check what applies to you rather than assuming.

Handling matters as much as the bag

Compliant packaging does not save you from poor practice. Store empty bags in their carton, off the floor, away from chemicals and out of direct sun. Handle bags with clean hands or gloves at the point of filling, and fill from a clean scoop or a dedicated chute. Keep the filled product below zero from the moment it is bagged to the moment it is sold, because a partial thaw and refreeze produces a solid block rather than cubes, and customers notice.

Sealing: twist ties or heat sealing

Hand tying with 75mm paper twist ties is fast, cheap and needs no equipment. Fold the top of the bag over once, gather it, and twist the tie around the gathered neck. It suits market stalls, service stations, small-batch producers and anyone bagging a few hundred units a week. Ties come in bundles of 1,000.

Heat sealing gives you a tamper-evident, fully closed bag and a tidier presentation. It suits higher volumes and any operation where the ice is resold through third-party freezers. The catch is that you need a sealer, and you need to seal above the fill line where the film is dry, because a wet seal will not bond properly. Most operations start with twist ties and move to heat sealing when volume justifies the equipment.

Working out what to order

Cost per bag drops sharply with carton quantity, which is why ice bags are sold in cartons of 1,000 and 2,000 rather than packs of fifty. To size your order, take your peak weekly ice sales in bags, multiply by the number of weeks you want to hold, and add a buffer for summer.

Demand for ice in Australia is brutally seasonal. A run of 35 degree days will clear a freezer, and that is exactly when everyone else is reordering too. Empty bags store flat, take up little space and have no meaningful shelf life limit, so buying ahead of summer costs you almost nothing and saves you a scramble.

If you need a size outside the standard range, or you are ordering at a volume where the standard carton price is not the right conversation, request a quote and we will price it properly. Freight and lead time questions are covered on our help and FAQ page.

Frequently asked questions

What size ice bag do I need for 5kg of ice?

A 350 x 620mm bag holds 5kg of cubed ice comfortably, with enough headroom to fold the top and tie it off. Bags are sized larger than the nominal weight on purpose, because ice does not pack tightly and you need room to close the bag properly.

Can I use ordinary plastic bags for ice?

You can, but they tend not to last. Standard poly bags are not specified for sub-zero use, so the film can go brittle and split along folds and seals in the freezer. You also need to be confident the material is suitable for food contact. A purpose-made freezer grade ice bag solves both problems. For portioning smaller quantities in a kitchen or bar, resealable ziplock bags are a better fit than an ice bag.

Are ice bags reusable?

They are single use in a retail context. Once a bag has been opened by a customer it should not be refilled and resold, for food safety reasons. For personal use at home, a bag can obviously be reused for non-food storage, but do not reuse bags in a commercial operation.

What is the difference between the 25µm and 50µm bags?

More than just thickness. The 25µm bag is HDPE, a denser and stiffer film that delivers strength at a lighter gauge. The 50µm bag is LDPE with a linear low additive, a softer film with more stretch and better puncture resistance. Both are specified for freezer use, and the difference in microns does not translate directly into a difference in strength because the materials are not the same.

Do I need to print my business name on ice bags?

Labelling requirements for packaged food vary depending on how the product is sold and where you are, so check with your local council or state food authority. Many operators print for branding reasons regardless. If you want printed ice bags, request a quote with your artwork and volume and we will come back with minimum order quantities and lead times.

How should I store empty ice bags?

Flat, in their original carton, off the floor, out of direct sunlight and away from chemicals or strong odours. Polyethylene picks up smells. Stored properly, empty bags keep for a long time, which is why buying a full carton ahead of summer makes sense.

The short version

Pick 3.5kg bags for retail freezer sales and 5kg bags for events, catering and volume ice. Buy freezer grade film, sort your food contact documentation before an auditor asks for it, and order cartons ahead of summer. Seal properly too, because a bag that leaks in a customer's boot is a customer who buys their ice somewhere else next time.