Other uses include bleaching flour, hair bleaching, teeth whitening, and textile bleaching. Some of these toothpastes contain peroxide, the same ingredient found in tooth bleaching gels. In-chair whitening is faster and more effective in comparison to the take-home bleaching options. Bleached corals continue to live but begin to starve after bleaching. These chemicals include but are not limited to bleaching agents and azo dyes. Intrinsic discoloration generally requires one of the many types of tooth bleaching. The production of chlorine and hypochlorite bleaching agents was a large consumer of manganese ores. Elevated temperatures can damage coral reefs, causing coral bleaching. It is also present in some tooth bleaching formulas. Preparatory stages may include&colon; soaking, hair removal, liming, deliming, bating, bleaching, and pickling. Historically, bromine was produced by adding sulfuric acid and bleaching powder to natural brine. Alkali treatment also neutralizes free fatty acids and removes color (bleaching). Cloth is prepared by washing and bleaching. The reef is also threatened by storms, coral bleaching and ocean acidification. Two oblique lines in the triangle prohibit chlorine bleaching.