Galvanizing and the Environment from Industrial Galvanisers

Although hot dip galvanized coatings have been around for over 150 years, they remain at the top of the list as the 'greenest' protective coatings for steel.

Hot dip galvanized coatings are formed by immersing steel in molten zinc. The zinc reacts with the steel to form an alloy with the steel. Hot dip galvanizing applies about 400 – 1000 grams of zinc to each square metre of the steel's surface. This equates to a coating thickness of about 50 to 150 microns.

This relatively thin film of galvanizing protects steel from corrosion for periods of 50 years or more in most applications. It is for this reason that hot dip galvanized steel is such an environmentally efficient construction material.

These outstanding credentials were among the reasons that hot dip galvanized steel was selected as one of the preferred materials of construction for the Sydney 2000 Olympics – the 'greenest' Games ever.

Other Environmental Facts About Galvanized Steel Are:

• It is 100% recyclable.
• There are no solvents or other ozone depleting components used in its manufacture or application. 80,000 tonnes of solvents are released into the atmosphere in Australia annually.
• It contributes 50% less greenhouse gases to the environment that concrete performing a similar function.
• 100% of the residues and effluents generated by the galvanizing process are recycled, re-processed or used in other waste management processes.
• There are no environmental or health effects associated with the use of hot dip galvanized products over time, unlike many paint coatings containing lead and other toxic pigments, solvents and construction materials such as asbestos.

Zinc and the Environment
The major component (99.5%+) used in the hot dip galvanized coatings on both Industrial Galvanizers' products and its customer's products is ZINC.

Natural background levels of zinc vary considerably depending on the nature of the medium and its geographical (and geological) location. In soil, zinc levels range from 10-300 mg/kg. Most Australian soils are zinc deficient.

Many plants, particularly grain crops, require zinc to ensure plant health and productivity, and Industrial Galvanizers through its Auszinc Metals & Alloys Division, is a major supplier of zinc additives to the fertilizer industry.

Humans may 'inherit' zinc deficiency through this shortage of zinc in the food chain, and in some areas in the Middle East, where cropping of the soil has been done for thousands of years, severe effects on humans have been identified as being the result of zinc deficiency.

Zinc is essential for human health and is vital in the functioning of more than 200 enzymes, for the stabilization of DNA and the transmission of signals through the nervous system.

The human body contains 2-3 g of zinc, which is found everywhere in the body and at its highest levels in the human reproductive system. Children and adolescents, pregnant and lactating women and elderly people have an increased zinc requirement.

The major source of zinc in food is found in shellfish (particularly oysters), red meat, poultry, fish, whole cereals and dairy products. Symptoms of zinc deficiency include reduced sense of taste and smell, skin disorders, mental lethargy and reduced libido and fertility.