About Recycling and Re-use of Tin box
Steel from cans and other sources is the most recycled packaging material. Around 65% of steel cans are recycled. In the United States, 63% of steel cans are recycled, compared to 52% of aluminium cans. In Europe the recycling rate in 2016 is 79,5%. Most can recycling occurs at the smelters, but individual consumers also directly reuse cans in various ways. For instance some people use two tin boxs to form a camp or survival stove to cook small meals.
Sustainability and recycling of steel beverage cans
From an ecological perspective, steel may be regarded as a closed-loop material: post-consumer waste can be collected, recycled and used to make new cans or other products. Each tonne of scrap steel recycled saves 1.5 tonnes of CO2, 1.4 tonnes of iron ore and 740 kg of coal. Steel is the world’s most recycled material, with more than 85% of all the world’s steel products being recycled at the end of their life: an estimated 630 million tonnes of steel scrap were recycled in 2017, saving 945 million tonnes of CO2.
Steel can recycling
Steel is a permanent material (a steel can can be recycled again and again without loss of quality). Recycling a single can saves the equivalent power for one laundry load, 1 hour of TV or 24 hours of lighting (10W LED bulb).
Steel beverage cans are recycled by being melted down in an electric arc furnace or basic oxygen furnace.
Most steel cans also carry some form of recycling identification such as the Metal Recycles Forever Mark Recyclable Steel and the Choose Steel campaign logo. There is also a campaign in Europe called Every Can Counts, encouraging can recycling in the workplace.
Smaller carbon footprint
All beverage packaging creates CO2 emissions at every stage in the production process, from raw material extraction, processing and manufacture through to recycling. However, steel cans are an ecological top performer, as cans can always be recycled. The steel industry needs the used cans and will use them in the production of new steel product. By recycling the cans and closing the loop, CO2 emissions are dramatically reduced. There is also the potential for higher global steel recycling rates as consumers become more aware of the benefits.
Dissolution of tin into the food
Tin is corrosion resistant, but acidic food like fruits and vegetables can corrode the tin layer. Nausea, vomiting, and diarrhea have been reported after ingesting canned food containing 200 mg/kg of tin. A 2002 study showed that 99.5% of 1200 tested cans contained below the UK regulatory limit of 200 mg/kg of tin, an improvement over most previous studies largely attributed to the increased use of fully lacquered cans for acidic foods, and concluded that the results do not raise any long term food safety concerns for consumers. The two non-compliant products were voluntarily recalled.
Evidence of tin impurities can be indicated by color, as in the case of pears, but lack of color change does not guarantee that a food is not tainted with tin.
Main article: Bisphenol-A
The chemical compound Bisphenol A found in can linings "...is associated with organizational changes in the prostate, breast, testis, mammary glands, body size, brain structure and chemistry, and behavior of laboratory animals", unborn children and adults.
Bisphenol-A (BPA) is a controversial chemical compound present in commercially available tin box plastic linings and transferred to canned food. The inside of the can is coated with an epoxy coating, in an attempt to prevent food or beverage from coming into contact with the metal. The longer food is in a can, and the warmer and more acidic it is, the more BPA leaches into it. In September 2010, Canada became the first country to declare BPA a toxic substance. In the European Union and Canada, BPA use is banned in baby bottles. The FDA does not regulate BPA (see BPA controversy#Public health regulatory history in the United States). Several companies, like Campbell's Soup, announced plans to eliminate BPA from the linings of their cans, but have not said which chemical they plan to replace it with. (See BPA controversy#Chemical manufacturers reactions to bans.)