Chicago Chemical Company

Nalco Water, an Ecolab Company, is a Naperville, Illinois-based supplier of water, energy and air improvement solutions and services for industrial and institutional markets. The company sells various products and services designed to reduce energy, water and other natural resource consumption, enhance air quality, minimize environmental releases and improve productivity and end products.

The company was founded in 1928 as the National Aluminate Corporation, formed from the merger of Chicago Chemical Company and the Aluminum Sales Corporation. By a series of mergers and acquisition, its name was changed to Nalco Chemical Company (1959 - 1999); then Ondeo Nalco Company (1999 - 2004); and in 2004 to Nalco Holding Company. It became a subsidiary of Ecolab Inc. in December 2011 after the completion of the US$5.4 billion acquisition by Ecolab.

Nalco Water serves more than 70,000 customers employing over 11,500 employees operating in over 130 countries. Among its products is Corexit - an oil dispersant widely used in the Deepwater Horizon oil spill.

The company traces its origins to 1928 in the United States with the establishment of National Aluminate Corporation - formed from the merger of Chicago Chemical Company and the Aluminum Sales Corporation. In 1959 it changed its name to Nalco Chemical Company; and in 1964, it became a publicly traded company listed on the . It acquired Industrial Bio-Test Laboratories in 1966.

The company was delisted from NYSE and renamed to Ondeo Nalco Company, following its 1999 acquisition by the French company, Suez (presently GDF Suez).

On 9 December 2003, the private equity group consisting of the Blackstone Group, Apollo Management LP and Goldman Sachs Capital Partners collaborated to acquire Ondeo Nalco Company from Suez SA for US$4.2 billion. The Company went public again, returning to the New York Stock Exchange in late 2004 under the name Nalco Holding Company.