Crack in California chemical tank averts ‘catastrophic’ blast but thousands remain evacuated

A crack that formed by chance in an overheated chemical tank in southern California relieved pressure and helped avert a catastrophic explosion, but officials said on Tuesday it still was not safe enough for 16,000 people living closest to the aerospace plant to return home. The crisis forced 50,000 people to evacuate in and near the Orange county city of Garden Grove last week. Most returned home after the crack formed over the Memorial Day weekend, but the risk of a smaller explosion or potential spill kept evacuation orders in place for about a third of residents. Exposure to methyl methacrylate – a highly flammable chemical used to make plastics – can cause serious respiratory problems, neurological problems and irritation to the skin, eyes and throat, according to the federal Environmental Protection Agency. The tank at GKN Aerospace Transparency Systems contains 6,000 to 7,000 gallons of the chemical. Underscoring the dangers of living near hazardous material was an implosion of a chemical tank at a pulp and paper mill in Washington state on Tuesday that injured at least 10 people, while an undisclosed number of others had been killed or remained missing. Crews at the California plant worked overnight to ensure two nearby tanks were neutralized and would not be affected by the compromised tank, the Orange county fire captain Brian Yau said, adding that material from one of these two tanks was transferred to another that has a neutralizing agent. …