Texas Industries Inc.'s cement plant in Riverside, Calif., was sued Monday by California Attorney General Jerry Brown, who said the plant exposes people to hexavalent chromium without providing required warnings.

Hexavalent chromium, a carcinogen present at levels as much as 50 times those requiring a public warning under California law, was traced to dust piles on a 4-acre plot at the cement plant, Mr. Brown said in a prepared statement.

The piles of dust are a byproduct of grinding and heating raw materials, according to the statement.

Kenneth Allen, a spokesman for Dallas-based Texas Industries, didn't return a call seeking comment.

Texas Industries rose 76 cents to $52.97.

Bloomberg News