Acerinox, S.A. (Spanish pronunciation: [aθeɾiˈnoks]) is a stainless steel manufacturing conglomerate group based in Spain.

The company was founded in 1970, and initially received technical support from the Japanese firm Nisshin Steel.

[3] In 1998, the Acerinox factory in Los Barrios, Cadiz melted a capsule of cesium-137 that was in a consignment of scrap metal.

[4][5] The radioactive substance was released into the atmosphere and spread over Europe — nuclear authorities in France, Germany, Italy, and Switzerland detected up to 2,400 microbecquerels of ionising radiation in the air, 1,000 times higher than the norm.

[5] During the clean-up, 7,000 metric tons of radioactive waste were dumped in Mendaña Marshes, Huelva.