Sustainability

The gleaming exteriors of New York City’s Chrysler (1930) and Socony Mobil (1954) buildings show the long term sustainability of stainless steel as an architectural material.

Photo: Nickel Institute,
Catherine Houska photographer

Sustainable design concepts are being integrated into a wide range of projects. This coastal private elementary school is in Pacific Palisades California. It was designed for a minimum service life of 50 years so low maintenance Type 316 (UNS S31600, EN 1.4401, SUS 316) was selected for the roof and exterior panels.

Photos: Millennium Tiles (www.millenniumtiles.com)

The Canadian National Archives were designed to have a 500-year service life. One aspect of achieving that was to select Type 316 L (UNS 31603, EN 1.4404, SUS 316L) for all of the structural components that are outside of the building envelope.

Photo: Nickel Institute

Stainless Steels’ Sustainable Advantage

Sustainability has become an important aspect of architectural design and comparisons of the environmental impact of construction materials have become common. When these analyses are done, stainless steel is consistently one of the most environmentally friendly construction materials used today.

In exterior applications, there is a direct correlation between corrosion resistance and long-term ‘sustainable’ performance. Corrosion can lead to aesthetic or structural failure and that can require premature replacement. When any material has to be replaced one or more times, the total environmental impact of a building is increased.

Sites with higher pollution levels, deicing or coastal salt exposure, and/or acid rain can have accelerated construction material deterioration. Molybdenum-containing stainless steels like Types 316, 444 and even more corrosion resistant alloys provide the necessary aesthetic and corrosion performance in these corrosive environments. The selection tools, case studies and resources provided on this website help decision makers select the right stainless steel for any environment.

Stainless steel is 100-percent recyclable with no down-cycling, regardless of how many times it is recycled. Stainless steel producers use as much recycled content as possible. In 2002, the International Stainless Steel Forum (ISSF) estimated typical recycled content was about 60%. The Specialty Steel Industry of North America (SSINA) issued a Fact Sheet stating that 300 series stainless steels produced in North America, like Type 316, have a post-consumer recycled content of 75 to 85%. As can be seen in Figure 1, this makes stainless steel one of the most environmentally friendly metals available for construction.

Table 1: Typical Recycled Content
Metal Product	Recycled Content (%)	EOL Collection Ratio (%)
Carbon Steel
Integrated mills	25-35	70 (sheet/strip)
Mini mills	≤95	97 (beams, plate)
Stainless Steel	60 - 85	>80
Zinc	23	33
Copper
Electrical wire	0	>90
Other products	70 - 95	>90
Aluminum (11)
Sheet	0	70
Extrusions	varies	70
Castings	≤100	70

Table 1: Typical Recycled Content and End-Of-Life Collection Ratio

Reference: “Comparing the Sustainability of Architectural Metals”, Catherine Houska and Dr. Steven Young, The Construction Specifier, July 2006, pgs. 80 – 90

Molybdenum-containing stainless steel conserves natural resources in many ways. It does not contribute to landfill waste or require frequent replacement. It is possible to use thinner stainless steel panels and reduce heat gain and air-conditioning costs through good design. Furthermore, stainless steel does not have to be coated to prevent corrosion, so no volatile organic compounds (VOCs) are released and there is no toxic run-off. Products manufactured from stainless steel are an excellent choice for protecting the environment and creating comfortable, attractive structures.