An evacuation alert was rescinded Wednesday afternoon for a one-mile ring around a Rohm and Haas Co. chemical plant near Houston after a dangerously overheated tank of highly flammable acrylic acid was cooled by firefighters, the company said. A mile-long stretch of the Houston Ship Channel, which had been closed as a precaution on Wednesday morning, was reopened at about 6:00 p.m. local time. It was the second evacuation along the row of refineries and plants near Houston in three days. On Monday, one person was killed and 74 injured by an explosion at the nearby Phillips Petroleum Co. plastics plant in Pasadena, Texas. A Rohm and Haas spokeswoman said workers at the plant detected the high temperatures at the tank on Wednesday morning.