Nippon Steel’s chromate-free tinplate

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Food safety and carbon neutral sustainability are among today’s major issues concerning the global food processing and packaging industry. Governments worldwide are tightening regulations controlling the use of potentially harmful chemicals and other materials in the production of food packaging.

At the same time, efforts to reduce CO2 emissions throughout the food production and packaging chain are increasing as companies respond to growing public demand for sustainable, environmentally-friendly products. Food cans are one category of food packaging that will require changes to the materials used in their production, as more countries adopt stricter packaging materials regulations.

During the past few years, several leading tinplate manufacturers have been developing new chromate-free tinplate products in preparation for the regulation that, from 2024, will require tinplate manufacturers in EU to comply with EU Article 95 REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations banning the use of chromium (VI)-containing chemicals in tinplate production.

Nippon Steel Corporation has introduced a new chromate-free tinplate (EZP) that is already being supplied to can manufacturers.

“Our new passivation process uses zirconium instead of chromium and is called EZP, which is good for both occupational safety and food safety,” explained Yujiro Shinto, general manager and head of the Tin Mill Products global marketing department in Nippon Steel’s Flat Products Unit’s Tin Mill Products & Electrical Steel Sheet division.

Commercially launched in Q4 2021, EZP is a zirconium-based inorganic system produced by a simple electrolytic process such as conventional chromate passivation that is used in traditional tinplate production.

In terms of its performance, EZP is equivalent to chromate passivation, Shinto said, and is compliant with United States Food & Drug Administration (FDA) and EU food contact safety regulations. Nippon Steel is Japan’s largest steelmaker and one of the world’s leading steel producers, with manufacturing bases in Japan and more than 15 countries worldwide. It operates three electrolytic tinplate lines and two tin-free steel lines in Japan, producing tinplate, tin-free steel and laminated steel sheets.

Under REACH regulations, the sunset date for sodium dichromate use has been set for 14 April 2024, following the earlier granting of a four-year review period by the EU starting on 14 April 2020, after requests for a delay in implementation were made by European tinplate manufacturers.

Cookie tin featuring the Ecoleaf logo. Image: David Hayes

“The EU decided to ban chromium in tinplate production from 2024, so EU tinplate manufacturers have to change their manufacturing processes and not use chromium-containing chemicals,” Shinto said.

“Some of our customers outside of Europe are also concerned about the spread of regulations banning the use of chromium-containing chemicals in future, and that the use of their current tinplate will be banned.”

While REACH regulations banning the use of chromium-containing chemicals are intended to address occupational health safety issues, food safety issues involving chromium are dealt with under Regional and National Specific Migration Limit (SML) limits on chromium migration into foodstuffs.

SML limits on chromium migration into foodstuffs, mostly set at 0.25 mg-Cr/kg-food, have been set by the EU; Nordic countries Denmark, Finland, Iceland, Norway and Sweden jointly; France, the Netherlands (0.1 mg-Cr/kg-food) and China (currently in draft form).

Nippon Steel’s EZP, being chromate-free tinplate, complies with all SML chromium migration limits. In addition, EZP meets the United States ASTM standard published in March 2022 as covered in ASTM Chapter 6 – Article 6.3 Optional Chromate Free Passivation Treatments; and Article 6.3.1 Cathodic Zirconium Based Passivation Chemical Treatment.

Shinto also noted that Nippon Steel has applied for compliance accreditation of EZP with ISO and Mercosur (the Southern Common Market). Both applications currently are being processed.

“The food safety side of changing the current tinplate production process to chromate-free is possible, that’s why more can manufacturer customers have started preparing. Gradually, the number of customers interested in EZP is growing all over the world,” Shinto said.

“In the EU, there is no ban on using the current tinplate, but to produce the current tinplate will be banned after 2024 due to REACH regulations, so some customers are thinking to prepare for the introduction of the stricter regulations.”

Japan currently does not have any REACH regulations concerning tinplate and TFS production. So, for the moment, Nippon Steel’s main target for EZP are its export markets. “It’s mostly foreign companies that are trying out our EZP, especially big food and beverage companies. A few customers already have started using EZP commercially while others have started to trial EZP. We expect EZP use will increase rapidly from now on,” Shinto said.

Meanwhile, as part of efforts to achieve the company’s ambitious 2050 Carbon Neutral target, Nippon Steel recently has launched a new brand, NSCarbolex, which features NSCarbolex Solution – advanced products and technical solutions that help reduce CO2 emissions in society; and NSCarbolex Neutral – steel products certified as reducing CO2 emissions in the steel-making process.

NSCarbolex Neutral will be provided with third-party certification (to ensure impartiality), in addition to Nippon Steel’s own official CO2 emission reduction certificate.

Shinto noted that Nippon Steel plans to use JIC Quality Assurance ( JICQA), which is established under Japan Inspection Corporation ( JIC), a leading Japanese inspection agency, as a certifying organisation.

Yujiro Shinto. Image: David Hayes

“We will launch NSCarbolex Neutral in the first half of 2023. The supply volume in 2023 is expected to be about 300,000 mt per year for all our different products,” Shinto said.

“Our customers are keen to see the company reduce its CO2 emissions, so they will be interested in all of our NSCarbolex products. We will adopt NSCarbolex Neutral for tinplate use in discussion with our customers.

“Nippon Steel will allocate the effects of carbon emissions reductions in the steelmaking process across Nippon Steel, as a whole, to all steel products manufactured by Nippon Steel, such as tinplate and others. Currently, we are introducing NSCarbolex Neutral’s features to our many customers.”

Nippon Steel has set challenging carbon reduction targets to show its commitment to sustainability as part of wider efforts by the whole of Japanese society to reduce the country’s CO2 emissions total. “In the past few years, the environmental issue around steel and tinplate has changed a lot. We cannot avoid the need to introduce an environment and sustainability response,” Shinto said.

“CO2 produced by the steel industry is about 14 per cent of the total carbon emissions in Japan, so reducing carbon emissions from steel production is very important.”

Recently launched, the company’s ‘Nippon Steel Carbon Neutral Vision 2050’ is a two-phase programme to achieve carbon neutrality. Phase one requires Nippon Steel to reduce CO2 emissions by 30 per cent by 2030, compared with emission levels in 2013. Phase two calls for carbon neutrality to be achieved by 2050.

“We must reduce CO2 emissions from our own manufacturing processes and contribute to society’s CO2 reduction with hi-tech products, so we have introduced NSCarbolex,” Shinto said.

“Carbon neutrality is a big challenge. We need to achieve three breakthroughs in technology which we will use to make not only tinplate but to make all our products.”

The first of the three necessary technology breakthroughs is the development of hydrogen injection into blast furnaces to reduce the blast furnace carbon emissions. The second breakthrough needed is the development of high-grade steel production in large scale electric furnaces. The third breakthrough that Nippon Steel is aiming for is development of 100 per cent hydrogen use to achieve indirect reduction in CO2 emissions.

Meanwhile, Nippon Steel already has obtained the EcoLeaf Environmental Product Declaration (EPD) certification for its many products including tinplate, tin-free steel and laminated steel sheets used for food and beverage cans and other container products. These are the first steel products for metal packaging to receive EcoLeaf certification in Japan, Shinto noted.

EcoLeaf is an EPD certification programme operated in Japan to disclose quantitative environmental information regarding the entire life cycle of a product. The EcoLeaf ecolabel is certificated by the Sustainable Management Promotion Organization (SuMPO), complying with the ISO 14025 international standard.

“We have received the EcoLeaf certificate so our customers can assess the environmental impact of their products when they use our products,” Shinto explained.

“We are promoting the EcoLeaf ecolabel on steel cans made with our tinplate, tin-free steel and laminated steel sheets.

“Using the LCA method for environmental information covers the entire product life cycle of a can, from mining ore through steel production and can making to recycling.

“The tinplate used in steel cans has low environmental impact in the production phase and is highly recyclable. This results in lower life cycle CO2 emissions in the steel products than those in other packaging materials.”

“The calculation methodology of environmental impact including recycling is established and internationally standardised as ISO 20915 standard for steel products only.”

Environmental information is useful not only for Nippon Steel customers, but also consumers wanting to live sustainable lifestyles.

“Customers who use our products can print the EcoLeaf ecolabel and use it on their own products, so consumers buying canned food and other canned products can feel they are participating in an environmentally-friendly action,” Shinto commented.

“Nippon Steel would like as many consumers as possible to be aware of this. To support this action, we use the EcoLeaf ecolabel for our tinplate products to contribute to building a sustainable society.

“Nippon Steel will continue to improve our technological capabilities and ability to propose services to support the development of the food industry, and to help improve people’s living standards by supplying tinplate.”

Starbucks can featuring the Ecoleaf logo. Image: David Hayes

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