Date: 29/11/2022 Shift: 9:00 AM – 12:00 PM Q. No: 227

Aluminium foil is aluminium prepared in thin sheets (in the order of 0.02 mm in thickness). As a result of this, the foil is extremely pliable, and can be wrapped around objects with ease. It is also often called tinfoil, although it is not made from tin, or as silver paper although it is not made from silver.
Aluminium foil typically has a highly reflective side and a more matte side. This is a result of common manufacturing processes. As aluminium foil is easy to tear, the foil is sent through machines in pairs. The side where the aluminium foil is in contact with the other sheet is more matte than the exterior side.
Millions of tons of aluminium foil are used throughout the world in the protection and packaging of foods, cosmetics and chemical products. Usually, an extremely thin layer is laminated to other materials, plastics and paper, to make long life packs for drinks, dairy products, and many other sensitive foods. The foil acts as a complete barrier to light (which spoils fats), odours, loss or gain of moisture and bacteria. Aluminium foil container and trays are used to bake pies and to pack takeaway meals, ready snacks and give long life to pet foods.
As is the case with all metallic items, aluminium foil reacts to being microwaved. This is due to the effect of electric field of the microwaves causing a build-up of charge to form between the sharp points in the aluminium; if enough charge accumulates it will discharge to a different place on the foil, creating a spark. Due to frequent use in food services, this commonly leads to kitchen fires.
The extensive use of aluminium foil has been criticised by some environmentalists because of the high resource cost of extracting aluminium, primarily as a result of the large amount of electricity used to decompose bauxite. However, this cost is greatly reduced via recycling and the fact that many foods that would otherwise perish can be protected over long periods without refrigeration.