Aluminum foil is a versatile household staple that helps us bake pies, line baking sheets and protect foods during grilling. It’s also a popular cooking tool that allows you to wrap meats and vegetables, keeping them moist and tender. However, while we may all use thin aluminum foil to line trays and cut down on cleanup time, many of us aren’t aware that this foil is dangerous to our health.
The main concern surrounding this household product is its toxicity, as it has been shown to be toxic at high doses. In 2006, the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Additives set a provisional tolerable weekly intake (PTWI) for aluminum of 1 mg/kg body weight per day, which has been reduced to 2 mg/kg by a recent re-evaluation (1).
thin aluminum foil is a great barrier against oxygen and moisture, which means that it can keep food fresh for longer than paper or plastic wraps. It is also very lightweight, making it easy to handle and store.
Manufacturers measure the thickness of their aluminum foil in mils, which are a thousandth of an inch. While you can buy foil in a variety of sizes, the most common is standard strength or Reynolds Wrap, both of which are 0.025 millimetres thick.
The thickness of aluminum foil depends on the alloy used for production, which is made by melting pure aluminum ingots. These are then rolled to the desired thickness using cold rolling mills. The cast-rolling method produces foil with two different sides, with the bright side being shiny and the matte side being dull. The brightness of the foil is determined by its reflectivity spectra, illustrated in figure 5 below.