American Charles Martin Hall and Frenchman Paul Héroult independently discover an industrial method for producing aluminium. The first full-scale production facility is ready in the United States in 1888. Until then, aluminium had been very expensive. The process requires large amounts of electricity - 50 to 60 kWh per kg. In 2009 Hydro consumed an average of 13.9 kWh per kg aluminium and we are working continuously to reduce this further.

NACO builds an aluminium plant in Høyanger, Norway. The vision is to build a green industrial city, with parks, avenues, houses and gardens, providing good living conditions for everyone. The driven project manager Sigurd Kloumann is responsible for the development. Earlier he has led Hydro's large-scale construction efforts in Notodden and Rjukan, both in Norway. NACO later becomes part of ÅSV, which is taken over by Hydro in 1986.

Vereinigte Aluminium-Werke AG (VAW) starts producing aluminium in Lauta in Germany. In the same period, Erftwerk starts production in Grevenbroich. Erftwerk is later aquired by VAW, which is finally acquired by Hydro in 2002.

VAW starts up a rolling mill in Grevenbroich, Germany. The annual production is 150 tonnes of aluminium foil. VAW is acquired by Hydro in 2002.

ÅSV starts producing aluminium in Årdal in Norway after a plant that was begun by German interests during World War II is completed. Construction during the war was carried out largely by forced laborers. ÅSV and the Årdal plant are acquired by Hydro in 1986.

The Norwegian Parliament appoints a "Smoke Damage Commission", largely triggered by fluoride damage caused by aluminium production at Årdal. This is one of the forerunners to the Norwegian Pollution Control Authority (SFT), which is established in 1974 and later becomes The Climate and Pollution Agency (KLIF) in 2010. In 1958, Hydro employs the first engineer who has the job of measuring and assessing dust emissions.

Hydro moves into the aluminium industry with the establishment of Alnor together with the U.S. company Harvey Aluminum Inc. The company uses contemporary Søderberg technology. With mostly open cells, the work environment in the smelters is far from ideal. Later Hydro develops its own technology, which provides a cleaner indoor environment, reduced external emissions and lower energy consumption.

Hydro establishes its own environmental department at its facilities in Porsgrunn. At the same time, the Norwegian Institute for Air Research establishes its own laboratory in the same area, with automatic monitoring of industrial air pollution. When SFT is established in 1974, this laboratory is converted to SFT's first operational district unit.

In 1971-1972, Hydro and BP conduct one of the world's first environmental impact studies for an industrial project, prior to the planned construction of the oil refinery in Mongstad.

Hydro begins a costly multi-year program to improve environmental standards in its industrial plants in Norway. New and improved processing and treatment technology is developed. For Hydro, this is a requirement to obtain government approval to build new petrochemical industries.

Hydro's management decides to give a higher priority to environmental issues. Rolf Marstrander, former director at the Norwegian Pollution Control Authority, is appointed as Hydro's first environmental director. A more systematic and long-term approach to environmental work is initiated.

Two employees are killed and one is critically injured when the ammonia plant at Hydro's Herøya plant in Porsgrunn, Norway explodes. The accident is a tragic reminder that petrochemical production can be very dangerous.

The aluminium metal plants at Høyanger, Årdal and Sunndal in Norway struggle with serious emission problems. When these plants are acquired by Hydro, improvements are made not only in technical areas, but also in attitudes, motivation and practices. Fluoride emissions are greatly reduced without the need for major initial investments.

Hydro's environmental profile is under strong attack from both non-governmental organizations and the Norwegian Pollution Control Authority. Much of the criticism is directed at the management of older environmental issues. Hydro sets a new direction for its environmental and safety activities, and a focus on this is built into the regular management and reporting systems. The company also publishes in 1989 one of the world's first environmental reports.

Hydro introduces specific guidelines for health, safety and environment that are applicable to all company activities. HSE requirements are also established for acquisitions and investments. In 1993 Hydro's environmental principles are added. They assess products using a life cycle perspective. This means the company will favor products that can be recycled or reused and will place corresponding demands on individual employees and suppliers.

Negative impacts from fluoride in the vicinity of smelters leads to a number of measures to reduce emissions from the middle of the 1980s. Norwegian aluminium producers initiate a study of environmental effects related to the Norwegian smelters. The report forms the basis for additional measures and future decisions. The study is still considered the most extensive ever completed on the environmental effects associated with aluminium production.

Hydro buys 34 percent of Brazilian Alunorte, which as the result of several expansions becomes the world's largest alumina refinery. One byproduct of alumina production is large amounts of red mud. The red mud depot at Alunorte is considered one of the best in the world.

Sunndal 4 opens in Norway. The new production line for aluminium is built with Hydro's proprietary electrolytic technology that delivers gains for the environment and production. This technology is developed further for use in Qatalum. There is a focus on reducing greenhouse gas emissions from the so-called anode effect - work that will later be applied at Hydro's other aluminium plants.

The closure of Hydro's Søderberg-based plants starts in Høyanger. A similar plant is closed in Årdal in 2007 and the company's last Søderberg plant in Karmøy is shut down in 2009. The plants are closed for environmental reasons and the closures contribute to a significant improvement in energy consumption and emissions.

Hydro opens its first energy-neutral building, in Bellenberg, Germany. Measurements show that the building produces more energy than it uses.

Following extensive construction efforts, production starts at Qatalum. The smelter plant uses the same technology as Hydro's most energy-efficient plant Sunndal 4, thereby ensuring lower emissions.

Hydro acquires Vale's substantial aluminium operations which include bauxite mining, alumina refining and aluminium production in Pará in Brazil - an area which is home to significant biological diversity.

A new environmental strategy is established to reduce Hydro's footprint, help our customers improve their footprint and improving aluminium as a material.