# Metal Metal has been widely used as food packaging since the early 19th century. The invention of the canning process made it possible to not only store but also conserve food directly in the packaging. Metal food packaging, such as aluminum cans and steel tins, is primarily composed of metal alloys. Aluminum packaging includes over 90% aluminum with other metals like copper and zinc, while steel packaging is often tin-coated. Metal packaging is durable and offers strong protection against gases, light, and odors, which, combined with its ability to withstand high temperatures, makes it a popular choice for food storage and preservation.

Different types of metal food packaging items.

*** ### Environmental impact The extraction and production of metals have several environmental impacts, including greenhouse gas emissions, emissions of other contaminants to air and water, and production of other waste. Metals are among the most recycled materials: the production impacts can be significantly reduced when scrap metal is reprocessed into new items. *** ### Chemical safet**y** Direct contact between food and metal can cause undesirable interactions, so some types of metal packaging are typically coated with organic polymers to prevent metal ions from migrating into the food. These coatings can release harmful chemicals, such as [bisphenol A](https://www.foodpackagingforum.org/resources/background-articles/bisphenol-a) and other substances into the food. Stainless steel is one type of metal that does not require a coating and significantly reduces concerns for chemical migration. *** ### Recovery At the end of its life, metal packaging has varied recycling possibilities. Aluminum and steel cans can be recycled repeatedly, preserving the quality of the metal. Recycling processes for aluminum involve shredding, removing coatings by heating, and melting the material to form new cans. Steel cans are separated magnetically, cleaned, and detinned before being melted and recast. Both materials' recycling processes are energy-intensive but significantly reduce the need for new raw materials compared to the production of virgin metals. However, items with thin metal layers, like beverage cartons, are often not recyclable due to technical and economic limitations. Similar to glass, the durability, recyclability, and inertness of metals make them excellent candidates for reusable foodware and packaging. *** ### More resources on metals If you want to learn more about metals, please visit the pages linked below.
Food Packaging Forum fact sheet: Metal/files/eUY5M82NPwdx8QoAf3gthttps://foodpackagingforum.org/wp-content/uploads/2021/06/FPF_Factsheet_Metal_v1.pdf
FitNESS open courseware: Metal/files/BsRPYJHYFJzKDfmwKMxnhttps://fitness.agroparistech.fr/fitness/lectures/html/common/S1/U1.2/part3.html#/2
--- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://help.upscorecard.org/background-information/food-contact-materials-fcms/metal.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.