| In Europe, the life span of zinc is 40 years (polluted industrial environment) and 100 years (unpolluted rural or urban environment). |
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| We say that zinc is durable because, in the presence of water, when it comes into contact with the oxygen and carbon dioxide in the air, a compact patina is formed, which adheres to the zinc, does not dissolve easily in rainwater and protects the zinc from any later atmospheric corrosion. |
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| Patina is the layer of zinc hydroxycarbonate that forms on the surface of the zinc when it is exposed, in the presence of water, to the oxygen (O2) and carbon dioxide (CO2) in the air.
The patina consists of a compact protective layer, which adheres to the zinc beneath it, does not dissolve easily in rainwater and protects the zinc from any later atmospheric corrosion. |
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| The amount of zinc in the environment, including the zinc emitted by man, does not present a risk to ecosystems because they are within a range of concentrations that are optimal for life. In this sense, zinc does not pollute. |
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| No, zinc is not harmful to human health or living organisms, nor is it toxic in itself since it is necessary and indeed essential in small quantities for all living organisms whether they are human, vegetable or animal. They draw it from their food in order to ensure that their metabolism functions properly. Zinc is essential for human health, for example for growth and for the protection of the skin. It also plays an important role in the development of the brain, foetal development, immune functions, sense of taste, sense of smell, etc. |
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Yes it is potentially100% recyclable.
In practice, it is 90% recycled in western Europe. Recovered zinc is reused by secondary zinc refiners and brass and zinc oxide producers but it is not used in the production of rolled zinc. |
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| White rust is the result of a corrosion mechanism that occurs when water condenses on poorly ventilated zinc surfaces. To prevent it from forming, there must be good ventilation between the rolled zinc and its substructure. . If it’s not possible to achieve such a ventilation we recommend to use VM ZINC PLUS, actually a VM ZINC receiving during the production a protection on it’s under surface. |
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It is an attack on the patina by atmospheric pollutants.
Sulphur dioxide is the main corrosive agent in urban or industrial environments.
The combination of chlorides and sulphur dioxides is the main factor in industrialised maritime regions. |
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Run-off is the amount of zinc that enters the environment.
The patina is attacked by certain atmospheric pollutants. The most soluble products formed during this attack are washed off by rainwater and released into the environment. This is what we refer to as run-off. |
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No, the amount of zinc released is lower than the amount of corroded zinc.
In fact, when the patina is attacked by atmospheric pollutants only the most soluble part is emitted into the environment, the less soluble part stays on the surface of the zinc. |
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| It has dropped and is still dropping at a fast pace. In fact, measures to fight atmospheric pollution have led to a general reduction in the amount of SO2 in the atmosphere. Since the corrosion rate is directly related to this, it is also being reduced. |
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The corrosion rate of an exposed rolled zinc surface is influenced by:
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sulphur dioxide (SO2), typically found in very urbanised or industrialised atmospheres |
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chlorides, essentially present in a marine atmosphere |
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the slope and direction of the exposed surface |
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surface treatments. |
SO2 has the greatest impact: it is very soluble in rainwater which it acidifies. It attacks the protective layer of zinc hydroxycarbonate (patina) to form a soluble zinc sulphate which is washed off by rainwater. The corrosion rate of zinc is thus higher in very industrialised areas. |
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| The coating used to galvanise zinc is made up of a layer of zinc on the surface covering layers of intermetallic zinc-iron compounds. The superficial layer of zinc behaves in the same way as rolled zinc in identical conditions. The corrosion rate is therefore comparable during the first years of exposure. |
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| Yes zinc can be used in a marine atmosphere because the durability of zinc in this type of atmosphere is the same as in an urban environment. However, the use of bilacquered or pre-weathered zinc is recommended in an industrialised marine atmosphere which is more aggressive and in an urban or industrialised atmosphere. |
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| No zinc doesn't require any particular protection because it protects itself by forming a patina when it comes into contact with the oxygen and carbon dioxide in the atmosphere. Nevertheless, the use of pre-weathered or bilacquered zinc may be recommended in particularly aggressive environments such as an industrialised areas or industrialised marine environments. |
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The only materials with which zinc is not compatible in the case of direct contact are:
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metals such as copper, brass, steel, cast iron and chrome |
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wood with an acid pH, for example: chestnut, oak, larch, birch, Douglas fir, and red cedar |
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cement and plaster |
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bitumen, even when not in direct contact but simply close to it. |
However, if precautions are taken to avoid direct contact, zinc can be used with all types of substructures. |
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The concept of sustainable development came into being in the Seventies. Public opinion woke up to the close link between the protection of the environment and the ecological, economic and social differences between countries and generations.
Sustainable development is a form of development which "meets the needs of the present without compromising the ability of future generations to meet their own needs." (from the Brundland Report, UN, 1987). It is development which respects the environment and takes into account the economic, technological and human equilibrium on a worldwide scale. |
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There are 3, each with its own specifications:
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HQE in France |
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LEED in the USA |
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Eco-devis in Switzerland |
The purpose of all three is to optimise the environmental performance of buildings. |
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Zinc is an asset with regard to environmental guidelines because some of its properties contribute to protecting natural resources, reducing greenhouse gases and limiting costs related to waste management and building maintenance.
These properties are:
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low energy consumption for the production of rolled zinc |
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high recovery and reuse rate (90%) |
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extremely durable |
Moreover, the variety of textures and colours (natural, pre-weathered, bilacquered) allows the building to blend into its surroundings, which is also an asset. |
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Rocks, many minerals, soil, water and the air naturally contain variable concentrations of it.
There is an average of 80 g of zinc per ton in the earth's crust.
In some areas of the earth's crust, as a result of geological and geochemical processes, there are particularly high concentrations of zinc. In areas where the concentration of zinc is generally over 5% the ore is extracted. |
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| Taking into account the efforts made to recycle it and with an estimated 1,900 million tons of mining reserves, mankind's requirements for zinc will be met for over a century. |
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| In the industrialised countries, production plants have to obey very strict environmental regulations. The French Umicore plants are all committed to meeting ISO 14001 standards: the Umicore plant in Viviez obtained ISO 14001 environmental certification at the end of 2003. The Auby plant obtained this certification at the beginning of 2004 and the Bray-et-Lû plant plants to have ISO 14001 by the end of 2004. |
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The main regions and countries where zinc ore is mined are:
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Asia (China, Kazakhstan, India, Japan) and Australia: 44%, |
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North America (Canada, USA, Mexico) and South America (Peru, Bolivia, Brazil): 43%, |
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Europe (Ireland, Poland, Spain): 10%, |
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Africa (Morocco, Tunisia): 3%. |
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Less energy is used to produce metallic zinc from ore or from recycled materials than for any other metal, such as aluminium, copper or stainless steel, used in the building industry.
In addition, less energy used to transform zinc into rolled zinc than to process other metals. In fact, zinc's mechanical properties make it easier to roll and transform it into finished products for the building industry because these properties allow the zinc to be rolled at a low-temperature compared to most other metals, thus reducing energy consumption. |
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Rolled zinc recycling is a traditional market in Western Europe where old rolled zinc is recovered during light building renovation work such as the replacement of rainwater systems or from bigger renovation projects such as the replacement of a roof and, occasionally, the demolition of an old building.
Systematic collection is facilitated by the ease of dismantling old products, the existence of a large local network of buyers and an advantageous purchase price. In fact, The long-term trend for the price of old zinc is relatively constant and equal to 60 to 75% of the London Metal exchange price for pure zinc ingots.
The main users of old rolled zinc products are secondary zinc refiners (56%), zinc oxide producers (35%) and brass producers (5%), all located in Europe. This recovered zinc cannot be reused to make rolled zinc: very pure (99.995%, therefore with a maximum of 0.005% impurities) primary zinc is required to make rolled zinc. |
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| Zinc deficiency can cause serious health problems. Zinc is the 3rd most important trace element after magnesium and iron in the human body. As such, it participates in a great number of metabolic reactions. A lack of zinc in the diet can give rise to serious health problems such as skin problems, slower healing of wounds, reduced senses of taste and smell, increased risk of infection, retarded growth in children, mental lethargy, lack of appetite, hair loss, etc. |
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In very specific exposure conditions in the work environment (when cutting or soldering galvanised steel at a high temperature where smoke containing micro particles of zinc oxide forms) people can develop metal fume fever whose symptoms are a dry, painful throat, a cough, headache and a temperature.
Moreover, accidental ingestion of a very large quantity of zinc (12,000 mg) has resulted in the following symptoms: dizziness, lethargy and difficulty in writing and walking.
he development of the brain, foetal development, immune functions, sense of taste, sense of smell, etc. |
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No, zinc is not a heavy metal in the same sense as cadmium for example.
Metals are commonly divided into two groups: "heavy" metals (with a density of over 5 g/cm3 (1)) and light metals (with a density of less than 5 g/cm3). Since the density of zinc is slightly higher than 5 g/cm3 it can certainly be classified as a "heavy metal" because of its density.
But the term "heavy metal" is often associated with "toxic". While this association is true for certain metals such as cadmium (if even a small quantity of these elements is inhaled, ingested or enters the human body through the skin, it can cause death or chronic or acute problems(2)). This is not true for other metals such as zinc or copper. Zinc is not toxic because it is a trace element which is indispensable for all living organisms.
(1) "Effets des métaux lourds sur l'environnement et la santé" (Effects of heavy metals on the environment and health) G. MIQUEL, Rapport 261 - Office parlementaire d'évaluation des choix scientifiques et technologiques.
(2) Décret n°97-517 du 15 mai 1997 relatif à la classification des déchets dangereux. (Order 97-517, May 15 1997 regarding the classification of dangerous waste.) |
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Ecotoxicology is the science that studies the potential effects of various substances on ecosystems (ecosystem = biological community of interacting living organisms and their physical environment, for example: a tree trunk, a field, an ocean, etc.).
The science that studies the potential effects of various substances on human beings is called toxicology. |
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No, in the developed countries, current emissions of zinc into the environment present no ecotoxicological risk.
Zinc is a natural element which is found throughout the environment (water, air, soil and rocks).
Localised emissions of zinc into the environment can be from natural sources such as volcanic emissions, or be of human origin, for example: worn tires, atmospheric corrosion from galvanised steel or rolled zinc, from fertilisers and cattle fodder.
In the developed countries, the amount of zinc measured in sensitive ecosystems shows that current emissions of zinc into the environment do not present any ecotoxicological risks because they are within the limits required for optimal conditions for life. |
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Not all the zinc emitted into the environment can be assimilated by living organisms. Only 10% in the ground and 30% in European rivers can be assimilated, the rest is in bound form and cannot be assimilated.
Zinc that can be directly assimilated by living organisms is classified as "bioavailable". |
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In the areas of energy, waste and water the building industry has ecological (energy consumption, emission of greenhouse gases, production of waste, etc.), economic (energy costs, waste management costs, water treatment costs, creation of employment, etc.) and social (organisation of living space, sanitary conditions, durability, etc.) impacts.
These impacts are all related to the three fundamental pillars of the concept of sustainable development.
The environmental quality approach in the building industry, whose aim is to reduce the negative impacts and optimise the positive impacts of this sector on the quality, environment and economy of society, is therefore a form of application of the concept of sustainable development in the building sector. |
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The use of zinc in building applications contributes to sustainable development because:
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When zinc when zinc is used as a galvanising agent to coat steel it considerably lengthens the life span of steel products, reduces their maintenance costs and economises on the natural resources used to produce steel. |
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Zinc contributes to the durability of infrastructures and transportation systems on which modern society depends. Zinc thus contributes to social progress. |
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90% of all rolled zinc products are recovered. Natural resources are thus protected, there is less building waste in storage centres because of recycling, and jobs are created in the recycling market. |
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HQE (Haute Qualité Environnemental: high environmental quality) is a French approach whose aim is to incorporate the environmental, social and economic concerns arising from the concept of sustainable development, into development, rehabilitation and construction projects.
This approach is applied throughout the life cycle of the building (from construction to demolition) in order to reduce the impact on the outside environment, participate in the protection of natural resources, and, at the same time, create a healthy, comfortable interior environment.
HQE has established objectives for the improvement of the environmental quality of buildings. These objectives are broken down into 14 targets divided into 4 major themes: ecological construction, ecological management, comfort and health… |
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No, HQE is neither a label, a standard nor a regulation.
The high environmental quality approach is voluntary and evolving. The different players in the building industry are involved in this approach which is usually initiated by the owners.
Certification under HQE in the service industry is being tested, but if it becomes official it is nevertheless intended to remain voluntary. |
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| No there is no list of HQE materials. It would not be logical for there to be one in that the aim is not the environmental quality of one product in the system but the overall environmental performance of the system. |
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No, for, although the straight investment cost is often estimated to be 10% higher, the overall extra cost can be greatly reduced, by incorporating the possible savings in running costs particularly for energy, water, maintenance and transport.
For communities there should be a reduction in cost because costs generated by pollution, health, consumption of resources and investments in energy in particular should be avoided. |
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It is an asset because it allows:
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A harmonious relationship between the building and its immediate environment (conforms to target 1): the rolled zinc products provide a wide choice of systems and a varied range of textures (natural, pre-weathered) and colours (lacquered). |
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Limitation of environmental impact (conforms to target 2): the amount of energy required to produce rolled zinc products is the lowest in the non-ferrous metal market. 90% of these products are recyclable at the end of their life. |
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A low pollution factor on the building site (conforms to target 3): fast installation of rolled zinc products, no on-site pollution and very little waste from the site. |
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Limitation of impact related to maintenance and upkeep of the building(conforms to target 7): the rolled zinc products are very durable. |
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Protection from noise inside the building (conforms to target 9): zinc is a non-ferrous metal that does not act like a drum, its acoustic attenuation index is comparable to that of slate. |
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| Leadership in Energy and Environmental Design, is an American guide created by the US Green Building Council for players in commercial construction. Its aim is the development of durable, "green" architecture. |
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| The use of rolled zinc in an American commercial building can contribute to obtaining LEED certification in the Materials and Resources category because it contributes to the protection of natural resources: rolled zinc is 100% recyclable. Because products can be recovered easily at the end of their life and there is an extensive network of buyers offering advantageous prices the recycling rate for zinc at the end of its life is extremely high (90% in western Europe). |
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What is the life span of a zinc roof?