Start with the job
Not as interchangeable products. A bin liner, food-storage zipper bag and cling-film roll have different intended jobs. Our selected UK examples are a 30-count Tesco 50 L bin-liner pack, a 12-count Bacofoil 3 L zipper-bag box at Waitrose, and a Waitrose 40 m by 350 mm non-PVC film roll. The lowest unit price among them does not establish a substitute for either other task.
Read three actual purchase units
The observed prices are £2.25, £3.35 and £2.50 respectively. The first two can be counted per matching bag, but a waste bag is not an approved food-storage bag. Film is purchased by a declared width and length rather than a fixed number of food portions. No leak, seal, strength or food-contact trial was performed here.
Keep food-contact scope separate
The Tesco selected source explicitly does not recommend the bin liner for food use. The zipper source describes food storage/freezing and its own care limits. The selected film source has particular microwave and oven restrictions. Those conditions do not transfer across a brand family, a plastic appearance or a shared litre number.
Choose the right comparison
Save the exact product code, task and supported quantity before comparing prices. Use the product-field finder for source limits and the ledger for an appropriate denominator. Unknown dimensions, heating applications or local disposal acceptance remain unknown. Current received packaging and independent material/food-contact/content review are still pending.
A purchase case to keep explicit
For a shopping list covering both rubbish and lunch storage, create two task rows even if both items are called bags. Keep film as a third row. A lower per-bag amount is useful only after the product’s actual intended use is settled;it cannot justify moving waste liners into the food-storage category.
Sources & scope
Checked November 5, 2026. Manufacturer and retailer references support the specific statements. Dated displayed prices are not final checkout quotes, performance rankings or performance testing. This shopping reference does not replace the exact product label or retailer instructions. Current received labels and independent materials/food-contact/content/commerce review remain pending.
Tesco GB tie-handle bin liners321788728 ↗